What is a business continuity plan?

A$.$ A plan explaining the use of only a single element of validation or verification to prove the identity of a subject.

B$.$ A plan outlining the failure response that results in open and unrestricted access or communication.

C$.$ A plan to maintain the mission$-$critical functions of the organization in the event of a problem that threatens to take business processes offline.

D$.$ A plan to restore the mission$-$critical functions of the organization once they have been interrupted by an adverse event.