单选题

以下哪个操作可以开启数据包的转发功能？

Question

A. sysctl -w net.ipv4.ip_forward=0

B. sysctl -w net.ipv4.ip_forward=1

C. sysctl -w net.ipv4.ip_forward=2

D. sysctl -w net.ipv4.ip_forward=3