ANSWER : OPTION D
Method-
128 64 32 16 8 4 2 1
0 1 1 1 0 0 0 1 --- (113 last octet of first address)
0 1 0 1 1 0 1 1 ----(91 last octet of second address)
Now, first MSB and second bit matching but 3rd bit is different.
so , we need 3 continos one's in mask, for different network.
So mask will be 255.255.255.224
@Arjun Sir please check , this method is also right or not?