I'm not sure what your options are, but here's what I've come up with:
The reason for our tardiness was because we got stuck in traffic.
Answer:
D) Why do her friends have to be mailed abroad?
Explanation:
Another way of asking the question, "Why does she have to mail her friends abroad?' is option D which says, "Why do her friends have to be mailed abroad?"
This is because, they are both saying (or asking) the same thing which is to ask why her friends have to be mailed abroad.
