Given the following routing table

Kernel IP routing table

Destination Gateway Genmask Flags Metric Ref Use Iface

192.168.178.0 0.0.0.0 255.255.255.0 U 9 0 0 wlan0

Why does the command route add default gw 192.168.1.1 fail?

A. Because there is no route to 192.168.1.1.

B. Because only one route can exist at a time.

C. Because there is already a default route.

D. Because default routes can not be set manually.

E. Because default routes must be set with ifconfig.