What Function Does Tier 1of the XML Protocol Service,based on the Client

Multiple Choice

What function does Tier 1of the XML protocol service,based on the client requests and application requirements,perform?

A) It locates the appropriate key information for the client
B) Performs a data validation on a portion of the key
C) Automatically updates the firewall installed on the user's computer
D) Updates the cryptographic algorithms for the S/MIME