Geologists believe that the warning signs for a major earthquake may include sudden fluctuations in local seismic activity, tilting and other deformations of the Earth’s crust, changing the measured strain across a fault zone, and varying the electrical properties of underground rocks.


Geologists believe that the warning signs for a major earthquake may include sudden fluctuations in local seismic activity, tilting and other deformations of the Earth’s crust, changing the measured strain across a fault zone, and varying the electrical properties of underground rocks.

A. changing the measured strain across a fault zone, and varying

B. changing measurements of the strain across a fault zone, and varying

C. changing the strain as measured across a fault zone, and variations of

D. changes in the measured strain across a fault zone, and variations in

E. changes in measurements of the strain across a fault zone, and variations among


In-depth Explanation and Correct Answer Below (so you don’t see it while reviewing the question)

geologists believe that the warning

Geologists believe that the warning… Explanation

Geologists believe that the warning signs for a major earthquake may include sudden fluctuations in local seismic activity, tilting and other deformations of the Earth’s crust, changing the measured strain across a fault zone, and varying the electrical properties of underground rocks.

(A) changing the measured strain across a fault zone, and varying

Parallelism is off. “Changing” and “varying” don’t match “fluctuations” and “deformations”. We want a simple list of nouns indicating the warning signs for a major earthquake.

Signs include:

Fluctuations

Deformations

Changing

Varying

(B) changing measurements of the strain across a fault zone, and varying

Parallelism is off. “Changing” and “varying” don’t match “fluctuations”.

Signs include:

Fluctuations

Deformations

Changing

Varying

(C) changing the strain as measured across a fault zone, and variations of

Parallelism is off. “Changing” doesn’t match “fluctuations” and “variations”

Signs include:

Fluctuations

Deformations

Changing

Variations

(D) changes in the measured strain across a fault zone, and variations in

Signs include:

Fluctuations

Deformations

Changes

Variations

(E) changes in measurements of the strain across a fault zone, and variations among

This one looks somewhat parallel but the meaning is off. It should be changes in the strain. This one emphasizes changes in the measurements. Also, “variations among” doesn’t make sense. We’re not comparing variations among the electrical properties of several different groups of rocks. The questions is focusing on underground rocks in general and the variations in the electrical properties of those rocks.

Correct Answer: D

For some SC guidance, here’s a link to a breakdown of GMAT sentence correction.