要使4個(gè)連續(xù)的C類網(wǎng)絡(luò)匯聚成一個(gè)超網(wǎng),則子網(wǎng)掩碼應(yīng)該為( )。A.255.240.0.0 B.255.255.0.0 C.255.255.252.0 D.255.255.255.252