Datacenter access is controlled with proximity badges that record all entries and exits from the
datacenter. The access records are used to identify which staff members accessed the data
center in the event of equipment theft. Which of the following MUST be prevented in order for this
policy to be effective?

A.
Password reuse

B.
Phishing

C.
Social engineering

D.
Tailgating

Explanation:
Tailgating is the term used for someone being so close to you when you enter a building that they
are able to come in right behind you without needing to use a key, a card, or any other security
device. This should be prevented in this case.