I believe the answer is D. The birth rate in India is greater than in china.
This is because of the "one-child policy" that's enforced in China.
Sentence 4
The topic sentence should set up what the paragraph is going to be about. This paragraph is about both heroes of the 1940s and heroes of the present, and sentence four is the only sentence that includes both. It also provides an indication that the paragraph is going to be comparing both types of heroes to each other.
I would personally put A :)
A. is correct, because the semicolon separates the sentence.
