What is the purpose of a public key?

A.
To authenticate a network interface

B.
To encrypt a private key

C.
To authenticate a private key

D.
To be encrypted by a private key

Explanation:
Asymmetric algorithms use public and private keys for key encryption
and distribution and for digital signatures. When something is encrypted with a
private key, only the corresponding public key can decrypt it. If a specific public
key can decrypt something, then the user knows that the person with the
corresponding private key encrypted it in the first place. So the public key
authenticates that the proper private key was used.