The researchers at the Yellowstone Ecology Institute, sometimes in partnership with scientists from the National Park Service, _____ credited with...

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 researchers at the Yellowstone Ecology Institute,
  • sometimes in partnership with scientists from the National Park Service,
  [?] credited with documenting the recovery of wolf populations in the region.

Sentence 2:

• Their long-term study has provided crucial data
  • about predator-prey dynamics in restored ecosystems.

Understanding the Meaning

Let's start reading from the beginning:

• 'The researchers at the Yellowstone Ecology Institute'
  • This tells us who we're talking about - a specific group of researchers
  • 'The researchers' is our main subject - and notice it's plural (more than one researcher)
  • 'at the Yellowstone Ecology Institute' tells us where these researchers work

• 'sometimes in partnership with scientists from the National Park Service'
  • This gives us extra information about how these researchers work
  • Sometimes they collaborate with National Park Service scientists
  • This phrase is set off by commas - it's adding detail but not changing who the subject is

Now here's where we need to fill in the blank:

• 'The researchers... _____ credited with documenting the recovery of wolf populations'

Let's look at our choices:

• We're deciding between: is / has been / are / is being
• These are different forms of the verb 'to be' - some singular, some plural

What do we need here?

• Our subject is 'The researchers' - that's PLURAL
• Even though there's a long phrase between the subject and the verb, we still need a verb that matches our plural subject
• So we need: are (the plural form)

Now let's read the rest to see the complete picture:

• 'credited with documenting the recovery of wolf populations in the region'
  • This tells us what the researchers are being credited for
  • They've documented how wolf populations have recovered

• The second sentence adds more context:
  • 'Their long-term study has provided crucial data about predator-prey dynamics in restored ecosystems'
  • This explains why their work is so important - it gives us information about how predators and prey interact when ecosystems are restored

What do we notice about the structure here?

• The subject 'The researchers' is separated from its verb by descriptive phrases
• But those phrases don't change what the subject is or whether it's singular or plural
• 'Researchers' is plural, so we need the plural verb form 'are'

The correct answer is C. are

GRAMMAR CONCEPT APPLIED

Subject-Verb Agreement with Separated Subjects and Verbs

The verb in a sentence must match its subject in number (singular or plural), even when the subject and verb are separated by descriptive phrases or other information.

Here's the pattern:

Step 1: Identify the true subject

• The researchers at the Yellowstone Ecology Institute [subject = 'researchers' = PLURAL]

Step 2: Ignore intervening phrases

• 'at the Yellowstone Ecology Institute' - describes where (prepositional phrase)
• 'sometimes in partnership with scientists from the National Park Service' - describes how (additional detail set off by commas)
• Neither of these changes the subject or its number

Step 3: Match the verb to the subject

• Researchers (plural) → are (plural) (correct)
• NOT: Researchers (plural) → is (singular) (incorrect)

Common trap: Students might be distracted by singular nouns in the intervening phrases (like 'Institute') or might lose track of the subject through the long descriptive phrases. Always trace back to identify the true subject before choosing your verb form.

Application to this question:
Even though 'the Yellowstone Ecology Institute' is singular and appears right before the blank, it's not the subject - it's just describing where the researchers work. The subject is still 'researchers' (plural), so we need 'are' (plural).