To Be Most Effective, the Critical Incident Stress Debriefing (CISD)

To be most effective, the critical incident stress debriefing (CISD) teams need to be onsite within which time period after serious events ranging from the death of coworkers to acts of terrorism and natural disasters?

A) 12 to 24 hours
B) 24 to 48 hours
C) 48 to 72 hours
D) 72 to 96 hours