Which of the following is a form of input validation that looks for allowable characters or patterns and only allows those?

A. blacklisting
B clipping levels
C. whitelisting
D. traffic policing

C
Explanation: Input validation is the process of checking all input for things such as proper format, proper length etc. In many cases, these validators use either the blacklisting of characters or patterns or the whitelisting of characters or patterns. Blacklisting looks for characters or patterns to block. It can be prone to preventing legitimate requests. Whitelisting looks for allowable characters or patterns and only allows those.