In business negotiation， usually there are four steps：inquiry， offer，counteroffer and acceptance.Among these four，（）and acceptance are（）the two indispensable steps.

In business negotiation， usually there are four steps：inquiry， offer，counteroffer and acceptance.Among these four，（）and acceptance are（）the two indispensable steps.
A.inquiry
B.offer
C.counteroffer
D.none of them
正确答案：offer