Tormund Has Created a Set of Firewall Rules and Has

Multiple Choice

Tormund has created a set of firewall rules and has noticed that when there is traffic that matches a rule, the traffic allowed in one direction automatically allows traffic in the other direction for an active connection as long as there is at least one message going in either direction within 10 minutes. What is the name of that type of firewall?

A) Stateless
B) Stateful
C) Status-monitoring
D) Active-analysis