Bunuel
Driven by high birth rates in Muslim countries, Islam currently has
twice as many adherents worldwide as it had in 1970.
A. twice as many adherents worldwide as it had
B. double the amount of adherents worldwide as
C. double the adherents worldwide it has
D. two times more adherents worldwide than it had
E. twice the number of adherents worldwide as were
OFFICIAL EXPLANATION
Driven by high birth rates in Muslim countries, Islam currently has twice as many adherents worldwide as it had in 1970.A. twice as many adherents worldwide as it had
This answer choice it grammatically correct. It correctly uses the comparative form as .. as, applies the correct quantifier many (because adherents is a count noun), and uses the past tense (it had) to match the time expression at the end of the sentence (in 1970).B. double the amount of adherents worldwide as
Incorrect.
This answer choice is grammatically incorrect. The quantifier phrase the amount of cannot be used to describe adherents, which is a count noun.
What helps us identify this mistake is the following Stop Sign:
much, (a) little, less, the amount of
C. double the adherents worldwide it has
Incorrect.
This answer choice is grammatically incorrect. The verb has in the Present Simple tense does not match the time expression in 1970.D. two times more adherents worldwide than it had
Incorrect.
While this answer choice correctly uses the comparative construction more...than, it is stylistically flawed. Replacing twice with two times makes this sentence more wordy than it needs to be.E. twice the number of adherents worldwide as were
Incorrect.
This answer choice is grammatically incorrect. First, since the word as is not a part of the comparative as ... as, it can only serve as a conjunction beginning a clause, but what follows it is a fragment with no subject (were in 1970).
Secondly, the use of the verb were (as in how many adherents there are) does not logically fit in the comparison with the beginning of the sentence, which refers how many adherents the Muslim religion has.