The Nacional tree is a rare variety of cacao. Nacionals were thought to have gone extinct by the twentieth century...
GMAT Information and Ideas : (Ideas) Questions
The Nacional tree is a rare variety of cacao. Nacionals were thought to have gone extinct by the twentieth century due to a fungus. This fungus can spread from tree to nearby tree through the air and causes disease. But around 2013, cacao expert Servio Pachard located some of these Nacional trees. The trees were in the Piedra de Plata coastal forest, within a hard-to-reach valley in Ecuador. Conservationists inferred that the Nacional trees in Piedra de Plata might have avoided the diseases that wiped out the other Nacionales because ______
Which choice most logically completes the text?
early twentieth-century scientists did not know why so many Nacionals were becoming infected.
the ability of the fungus to travel through the air was only recently discovered.
they were too far from the other Nacional trees infected by the fungus to become infected themselves.
the chocolate made from their pods was highly valued.
Step 1: Decode and Map the Passage
Part A: Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "The Nacional tree is a rare variety of cacao." |
|
| "Nacionales were thought to have gone extinct by the twentieth century due to a fungus." |
|
| "This fungus can spread from tree to nearby tree through the air and causes disease." |
|
| "But around 2013, cacao expert Servio Pachard located some of these Nacional trees." |
|
| "The trees were in the Piedra de Plata coastal forest, within a hard-to-reach valley in Ecuador." |
|
| "Conservationists inferred that the Nacional trees in Piedra de Plata might have avoided the diseases that wiped out the other Nacionales because ______" |
|
Part B: Passage Architecture & Core Elements
Main Point: Some Nacional cacao trees survived extinction by avoiding the fungal disease that killed others, and scientists need to explain why these particular trees were spared.
Step 2: Interpret the Question Precisely
This is a fill-in-the-blank question asking us to choose the best logical connector. The answer must create the right relationship between what comes before and after the blank.
Step 3: Prethink the Answer
- We know the fungus spreads "from tree to nearby tree through the air," which means proximity matters for infection
- The surviving trees were in a "hard-to-reach valley" - this suggests isolation
- The logical connection would be that these trees were protected by distance - they were too far away from infected trees for the airborne fungus to reach them
early twentieth-century scientists did not know why so many Nacionals were becoming infected.
✗ Incorrect
- This focuses on what early scientists didn't know
- Doesn't explain why the Piedra de Plata trees specifically survived
- Knowledge gaps don't protect trees from disease
the ability of the fungus to travel through the air was only recently discovered.
✗ Incorrect
- This is about when the discovery was made about airborne transmission
- The timing of scientific discovery doesn't affect whether trees get infected
they were too far from the other Nacional trees infected by the fungus to become infected themselves.
✓ Correct
- Directly addresses the geographic isolation mentioned in the passage
- Connects logically with the fungus spreading "from tree to nearby tree through the air"
- Explains survival through distance - if there were no nearby infected trees, the airborne fungus couldn't reach them
the chocolate made from their pods was highly valued.
✗ Incorrect
- The economic value of chocolate is irrelevant to disease survival
- Doesn't address the fungal infection mechanism at all