See, the option they are given is all wrong. There is no rule that you have to subtract 2 from the number of subnets, yes we are going to subtract 2 from the number of hosts because all 0's and all 1's in host part are reserved for the network address and broadcast address for the respective subnet.
The rule that says subtract 2 is for class A only where all 0 and 127.x.y.z is reserved for special purposes, and that is why the range of class A is 1 - 126
So total number of subnet = 2 ^ 6 = 64
and number of hosts in each subnet is 2 ^ 10 - 2 =1022