Error in The Ultimate Guide to SAT Grammar or Blue Book

Test Preparation SAT Preparation
1

On page 156 for question 12 in Section 10 Erica says:

NE;concept tested = parallel structure, word pair (as…as)
NE standing for no error.

Now, in the Blue Book, the answer to question 12 is not A for no error, rather it is D. Here is the question:

The villagers found the visitors [equally as fascinating as their customs were] mystifying.
A. equally as fascinating as their customs were
B. equally fascinating and their customs
C. as fascinating and their customs
D. as fascinating as their customs were
E. as fascinating and their customs were

Now, I’m not sure which one of these is correct and would like to know what you think.

2

The answer is definitely (D) and the original [(A)] is redundant because “as…as” means “equally.”