问题详情

参加下图，出现默认网关Ping 不通的情况，出问题的协议层是（）。 C: >ping 10.10.10.1 Pinging 10.10.10.1 with 32 bytes of data: Request timed out. Request timed out. Request timed out. Request timed out. Ping statistics for 10.10.10.1: Packets: Sent=4 ，Received=0，Lost=4 (100% loss)

A.物理层B.网络层C.传输层D.应用层

请帮忙给出正确答案和分析，谢谢！