sujitmgmat wrote:

Thanks GMAT TIGER for responding. However, I am difficulty understanding it.

Statement 1 implies that either A = 0 "or" AB=1. From this how can we conclude that AB=1 is not possible?

Similarly Statement 2 implies that either B=0 "or" AB=1.

Therefore, Statement 1 and 2 will imply that AB=1. That is, I think answer should be (C).

But the answer in GMATCLUB Challenge is given as (E).

This is data sufficiency problem - since you have two options for AB (i.e 0 or 1) then you don't have sufficient data to answer the problem.

Assume A=0 B=0 then AB = 0 in option (C) !

the correct answer is (E)