A. It sends only five ping requests to the 172.18.1 destination.
B. It sends a continuous ping with a packet length of five bytes to the 172.18.1 destination.
C. It sends five rapid ping requests to the 172.18.1 destination.
D. It sends a continuous rapid ping with a packet length of five bytes to the 172.18.1 destination.
参考答案：B
