You can either,
Multiply the four choices a,b,c,d out.
or find each of there determinants.
If B is the inverse of A then AB= I
So the answer will be what two matrix multiply together to give the identity matrix.
Finding their determinants you say B is the inverse of A and Det(A) = 2, then Det(A-1)=Det(B)=1/2
This means Det(A)Det(B)=1 which means A and B are inverses.
I'd probably multiply them all out its good practice