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.