What needs to be done on the client to enable it to use the router as its default gateway?

A network client has an ethernet interface configured with an IP address in the subnet
192.168.0.0/24. This subnet has a router, with the IP address 192.168.0.1, that connects this subnet
to the Internet. What needs to be done on the client to enable it to use the router as its default
gateway?

A.
Run route add default gw 192.168.0.1 eth1.

B.
Run route add gw 192.168.0.1 eth1.

C.
Run ifconfig eth0 defaultroute 192.168.0.1.

D.
Add “defaultroute 192.168.0.1” to /etc/resolv.conf.

E.
Run route add defaultgw=192.168.0.1 if=eth0.

Explanation:
From the man pages:
route add default gw mango-gw adds a default route (which will be used if no other route matches).
All packets using this route will be
gatewayed through “mango-gw”. The device which will actually be used for that route depends on
how we can reach “mango-gw” – the static route to “mango-gw” will have to be set up before.