And, more importantly, why did they develop?

Question

Which revision changes this sentence to the indicative mood?

A.
And, more importantly, you might know why they developed.

B.
And, more importantly, do you know why they developed?

C.
And, more importantly, learn why they developed!

D.
And, more importantly, here is why they developed.

Answer 1

D.
And, more importantly, here is why they developed.