单项选择题

A.Both FastEthernet 0/0 and Serial 0/0/0 are trusted interface
B.Both FastEthernet 0/0 and Serial 0/0/0 are untrusted interfaces
C.FastEthernet 0/0 is a trusted interface and Serial 0/0/0 is an untrusted interface
D.FastEthernet 0/0 is an untrusted interface and Serial 0/0/0 is a trusted interface