"respond" and "answer"

[Pierce111]

Is that correct to say:
a) I answered on a question (problem).
b) I answered a question (problem).
c) I responded on a question (problem).
d) I responded a question (problem).

?

 

[Rover_KE]

Only 'I answered a question' is correct.

 

[Pierce111]

and for "respond":
"I responded to a question"
Is that correct?

 

[Rover_KE]

Yes.