What is the subnetwork address for a host with the IP address 201.100.5.68/28?

What is the subnetwork address for a host with the IP address 201.100.5.68/28?
A. 201.100.5.0
B. 201.100.5.32
C. 201.100.5.64
D. 201.100.5.65
E. 201.100.5.31
F. 201.100.5.1