A Linux systems administrator needs to persistently enable IPv4 forwarding in one of the Linux systems. Which of the following commands can be used together to accomplish this task? (Choose two.)

A. sysctl net.ipv4.ip_forward
B. sysctl -w net.ipv4.ip_forward=1
C. echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf
D. echo 1 > /proc/sys/net/ipv4/ip_forward
E. sysctl p
F. echo "net.ipv6.conf.all.forwarding=l" >> /etc/sysctl.conf