Two people can verify they are communicating with each other by using a which verifies each party's identity by being the distributor of public and private keys that both parties use. these keys are digitally signed so both parties can be assured they are communicating with each other.
select one:

a. hash authority
b. certificate authority
c. signature authority
d. digital signature

b. Certificate Authority

Explanation:

Based on the information provided within the question it can be said that they are communicating with each other by using a certificate authority. This term refers to a company or organization that provides security verification by issuing both parties cryptographic keys which are specifically verified by the company in order to allow both parties to know exactly who they are communicating with.