Option (C) is correct
here number of bits for subnet=6 bits
so maximum number of subnets =(2^6)-2 =62 subnets
(here 2 is subtracted because the network ID of 1'st subnet and the network ID of whole network will be same so we don't include subnet number 0 and DBA of last subnet and DBA of whole network will be same so we don't include the last subnet number i.e DBA subnet because of ambiguity)
in class B 16 bits for Net ID part and 16 bits for host ID part,here 6 bits are used for subnetting so 6 bits are borrowed from host ID part .
now the remaining bits=16-6=10 bits
maximum number of hosts per subnet =(2^10) -2 =1022 hosts