Which two characteristics describe the UDP protocol?（）

A. A subnet mask specifies the portion of an IP address that is in a binary format.
B. A subnet mask specifies the portion of an IP address that is in a decimal format.
C. A subnet mask specifies the portion of an IP address that represents a network prefix.
D. A subnet mask specifies the portion of an IP address that represents network hosts.

A. It is used in conjunction with the wildcard mask to determine the number of hosts on a network
B. It is used to define which parts of the IP address are allocated to host addresses and network prefixes
C. It is used to hide subnets from external networks by masking the subnets with NAT
D. It is used to differentiate a network as a classful network or a classless network

A. It is used to identify the maximum hop count of a subnetwork.
B. It is used to identify an IP address as either private or public.
C. It is used to identify the network to which an IP address belongs.
D. It is used to identify the total number of bits present in an IP address.