Hi Riya,

This is a test of parallelism

The parallel structure is – The twins were X but Y

X is “eager”

We are looking for the correct Y among the answer choices

A. were “eager” but “quickly tiring” – not parallel

B. were “eager” but “quick to tire” – parallel. We have adjectives on both sides

C. were “eager” but “tire quickly” – incorrect construction, no parallelism

D. were “eager” but “tired quickly” – same as C

E. were “eager” but “rapidly becoming tired” – not parallel