there are 3 times

In a certain population, there are 3 times ……………… twenty-one or under as there are people over twenty-one.

A. older than those of
B. as many people aged color=green
C. of people with the age of
D. as much as those whose age is

Would you please tell me why A, C and D are wrong?
Does “there are 3 times” need a special construction after it?

Thank you.

If you cannot see the problems with those options, then I really suggest that you find some exercises more suited to your English ability and build up to this type of level. I don’t think asking for people to point out the errors in specific examples is really of any worth to you.