What is the recommended approach to implement a login authentication call for an inbound integration call to Salesforce?

What is the recommended approach to implement a login authentication call for an inbound integration call to Salesforce?
A . Perform the login call only when the session/access token has expired or no longer works.
B . Perform the login authentication call before each integration call to Salesforce every time.
C . Only perform a single login call forever and store the session/access token permanently.
D . Perform the login authentication call before a single transaction of multiple calls to Salesforce.

View Answer

Answer: A