The Lion Light system, developed by Kenyan inventor Richard Turere, consists of LED lights installed around the perimeter of livestock...

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

Sentence 1:

• The Lion Light system,
  • developed by Kenyan inventor Richard Turere,
  consists of LED lights
  • installed around the perimeter of livestock pastures.

Sentence 2:

• Powered with energy [? comma placement ?] collected by solar panels during the day [? comma ?],
  the blinking LEDs
  • keep lions away at night,
    • thus protecting the livestock
      • without risking harm to the endangered lions.

Understanding the Meaning

The first sentence sets up what we're talking about:

• The Lion Light system
  • (a system developed by a Kenyan inventor named Richard Turere)
  is made up of LED lights
  • that are installed around livestock pastures.

Now the second sentence tells us how this system works.

It starts with:

• 'Powered with energy... collected by solar panels during the day'

This is where we have the blank. Let's look at the choices:

• A: energy collected, by solar panels, during the day
• B: energy collected by solar panels during the day
• C: energy collected by solar panels during the day,
• D: energy, collected by solar panels during the day,

What varies is:

• Whether there are commas WITHIN the phrase "collected by solar panels during the day"
• Whether there's a comma AFTER the phrase (before "the blinking LEDs")

To see what works here, let's read the rest of the sentence and understand what it's saying!

After the blank, we get:

• 'the blinking LEDs keep lions away at night'
  • This is what the LEDs actually DO - their main function
  • And this action protects the livestock without harming the endangered lions

Now let's understand the complete structure:

• The sentence opens with a descriptive phrase:
  • 'Powered with energy collected by solar panels during the day'
  • This tells us HOW the LEDs are powered - what makes them work

• Then comes the main part of the sentence:
  • 'the blinking LEDs keep lions away at night'
  • This is the core statement - what the LEDs do

What do we notice about the structure here?

• We have an introductory descriptive phrase followed by the main statement
  • These two parts need to be separated with a comma
  • So we need a comma AFTER "day" to separate them

• Within the phrase "energy collected by solar panels during the day":
  • "collected by solar panels during the day" tells us which energy we're talking about
  • This isn't extra information - it's essential to know what kind of energy
  • When information is essential like this, we DON'T use commas to set it off
  • All the parts flow together: collected WHERE? by solar panels. WHEN? during the day.

So we need:

• NO commas within "collected by solar panels during the day" (it's all essential information flowing together)
• A comma AFTER "day" (to separate the introductory phrase from the main statement)

The correct answer is Choice C: "energy collected by solar panels during the day,"

GRAMMAR CONCEPT APPLIED

Using Commas with Introductory Phrases and Essential Modifiers

This question tests two related comma rules:

Rule 1: Introductory phrases need comma separation

When a sentence begins with a descriptive phrase that sets up context, use a comma to separate it from the main clause:

• Introductory phrase: Powered with energy collected by solar panels during the day
• Main clause: the blinking LEDs keep lions away at night
• Correct: Powered with energy collected by solar panels during the day, the blinking LEDs keep lions away at night.

Rule 2: Essential modifiers don't get commas

When a modifier (called a restrictive modifier in grammar terms) provides essential information to identify what you're talking about, DON'T set it off with commas:

• Noun: energy
• Essential modifier: collected by solar panels during the day
• This tells us WHICH energy - not just any energy, but specifically this type
• It's essential to the meaning
• Correct: energy collected by solar panels during the day
• Incorrect: energy, collected by solar panels during the day, (comma suggests it's non-essential bonus info)

In this question:

• "collected by solar panels during the day" is essential information about the energy (no commas within)
• But the whole phrase "Powered with energy collected by solar panels during the day" is an introductory phrase (needs comma after it)