Personally, I would phrase it like this:
The choir moved the audience to tears with their beautiful voices.
The correct answer is a: The people behind us in line (at least a dozen by our count) arrived too late to get tickets. Parentheses () are often used to enclose additional information, a short explanation, an example, or comment. In this example, there is no need to capitalize the first letter within the parentheses. The last choice is a run-on sentence and incorrect.
Answer:
iy was historic moment for the american people