i renmenber ( ) to help us if wi ever got into troubleA.once offeringB.him once offeringC.him to offerD.to offer him选哪个?为什么?

i renmenber ( ) to help us if wi ever got into trouble
A.once offering
B.him once offering
C.him to offer
D.to offer him
选哪个?
为什么?

b 记得sb做过sth用doing