How Are Terrorists Different from Guerilla Fighters

How are terrorists different from guerilla fighters?

A) Guerilla fighters may attack civilians, but their focus is on security forces, whereas terrorists will attack anyone.
B) Terrorists may attack civilians, but their focus is on security forces, whereas guerilla fighters will attack anyone.
C) Terrorists focus solely on civilians, whereas guerilla fighters focus solely on security forces.
D) Terrorists focus solely on security forces, whereas guerilla fighters focus solely on civilians.
E) Guerilla fighters tend to be much more violent than terrorists.