Find the same meaning as "erase" in the last sentence of the first paragraph.

A．To show that a hacker is more dangerous than a thief.
B．To tell people that thieves like to steal computers nowadays.
C．To demand that a computer network should be set up against thieves.
D．To look into the case where hackers and thieves are the same people.

A．they will cost too much money
B．communication may be interrupted
C．hacking has not caused much damage
D．tough measures are illegal