What is the primary function of the IOS firewall in the SAFE SMR small network design?

What is the primary function of the IOS firewall in the SAFE SMR small network design?

A.
provide connection state enforcement and detailed filtering for sessions initiated through the
firewall

B.
authenticate IPSec tunnels

C.
provide hostDoS mitigation

D.
provide remote site connectivity and general filtering for sessions initiated through the firewall

E.
provide remote site authentication