Please answer this question correctly and asap. It's a Computer Security and Forensics class.

Computers in a LAN are configured to use a symmetric key cipher within the LAN to avoid hardware address spoofing. This means that each computer share a different key with every other computer in the LAN. If there are 100 computers in this LAN, each computer must have at least O 100 cipher keys O 99 cipher keys ?4950 cipher keys O 100000 cipher keys