When performing an installation you notice DHCP has set your Management Server subnet mask to 255.255.255.252. Based on EMC best practices, what is the appropriate subnet mask value for Management Server network 128.221.252.0?

When performing an installation you notice DHCP has set your Management Server subnet mask to 255.255.255.252. Based on EMC best practices, what is the appropriate subnet mask value for Management Server network 128.221.252.0?
A . 255.255.255.224
B . 255.255.255.248
C . 255.255.255.192
D . 255.255.255.128

Answer: A