Recently discovered fossil remains strongly suggest that the Australian egg-laying mammals of today are a branch of the main stem of mammalian evolution rather than developing independently from a common ancestor of mammals more than 220 million years ago.
A. rather than developing independently from
B. rather than a type that developed independently from
C. rather than a type whose developments was independent of
D. instead of developing independently from
E. instead of a development that was independent of
In-depth Explanation and Correct Answer Below (so you don’t see it while reviewing the question)
Recently discovered fossil remains strongly… Explanation
Recently discovered fossil remains strongly suggest that the Australian egg-laying mammals of today are a branch of the main stem of mammalian evolution rather than developing independently from a common ancestor of mammals more than 220 million years ago.
(A) rather than developing independently from
Australian egg-laying mammals are a branch of the main stem rather than developing independently. Parallelism is off between “a branch” and “developing”. Need to compare two nouns.
(B) rather than a type that developed independently from
Australian egg-laying mammals are a branch of the main stem rather than a type that developed independently. “branch” and “type” are parallel and make sense.
(C) rather than a type whose developments was independent of
Subject verb agreement: developments were. Australian egg-laying mammals are a branch of the main stem instead of developing
(D) instead of developing independently from
Australian egg-laying mammals are a branch of the main stem instead of developing independently. Parallelism is off between “a branch” and “developing”. Need to compare two nouns.
(E) instead of a development that was independent of
Australian egg-laying mammals are a branch of the main stem instead of a development. Australian egg-laying mammals aren’t a development.
Correct Answer: B
For some SC guidance, here’s a link to a breakdown of GMAT sentence correction.