Question

Which is the general question to following sentences?
(Выберите общий вопрос к следующим предложениям)
Tomorrow they are flying to Moscow.
Выберите один ответ:
a. Are tomorrow they flying to Moscow?
b. Where are they flying?
c. Are flying they to Moscow tomorrow?
d. Are they flying to Moscow tomorrow?

Answer 1

d. Are they flying to Moscow tomorrow?