Hi!
Well the idiom is: mistake + thing/person + for and eliminates thereby answer choices A,C and E.
When comparing B to D, one must chose between the call of the Mockingbird and the callING of the mockingbird.
The call of the mockingbird seems preferable in this sentence structure.
Early ornithologists often mistook the calling of the Mockingbird as the rare Rufous Sided Towhee
A. calling of the Mockingbird as the rare Rufous Sided Towhee
B. call of the Mockingbird for that of the rare Rufous Sided Towhee
C. call of the Mockingbird as the rare Rufous Sided Towhee
D. calling of the Mockingbird for that of the rare Rufous Sided Towhee
E. Mockingbird calling for the rare Rufous Sided Towhee
Well the idiom is: mistake + thing/person + for and eliminates thereby answer choices A,C and E.
When comparing B to D, one must chose between the call of the Mockingbird and the callING of the mockingbird.
The call of the mockingbird seems preferable in this sentence structure.
Early ornithologists often mistook the calling of the Mockingbird as the rare Rufous Sided Towhee
A. calling of the Mockingbird as the rare Rufous Sided Towhee
B. call of the Mockingbird for that of the rare Rufous Sided Towhee
C. call of the Mockingbird as the rare Rufous Sided Towhee
D. calling of the Mockingbird for that of the rare Rufous Sided Towhee
E. Mockingbird calling for the rare Rufous Sided Towhee