Answer: A
Explanation: While I'm not bilingual, and can't verify if that statement is correct, I do know it's the only "reason" on the list. B is a subjective experience and doesn't really prove anything, C is just different examples of languages and isn't a reason at all, and D is an example of something that could be done to support the claim, but not a reason why the claim is correct. A is the only one that really argues why all students should be required to learn a second language.
