Q)We wish to show that problem B is NP-complete. Which of the following facts is sufficient to establish this.

A)There is a polynomial time reduction from B to SAT.

B)There is a polynomial time reduction from SAT to B

C) There is a polynomial time reduction from B to SAT, and B has a checking algorithm.

D)There is a polynomial time reduction from SAT to B, and B has a checking algorithm.

I think option is B

Can anyone explain what is the answer??