The first Address in a Block should be exactly divisible by Number of Addresses in a Block
As here block contains 32 IP addresses means #of host bits=5
Let the IP address X.Y.Z.W as number of IP address is 32 so we only have to focus about W (last octet)
We have to guess about these 8 bits of W _ _ _ _ _ _ _ _ . as the number of host bits =5 and we have to tell first address of the block and we know for first address all host would be =0 and now if any of remaining 3 bits is 1 it would then multiply the 25 by some 2a .so ultimately it would become 25+a so that would certainly be divisible by 32 (the number of IP addresses). out of those option 3 and 4 are divisible by 32.
so option C,D are correct one.