Answer is option C).
255.255.255.224 will be written as 11111111.11111111.11111111.11100000
First three bits are netid and next 5 is used for hosts.
a)201.55.66.15 : 15 is 00001111 .In dba all host bits are 1. As only first three are netid all bits cannot be 1 here.
B)201.55.66.31 : 31 is 00011111. It is DBA for all network.Not only for particular subnet.
C)201.55.66.63: 63 is 00111111 .This is DBA for neid 001 ANd where all host bits are 1.