Vince Is a Soldier in the Military and Has Been

Vince is a soldier in the military and has been stationed in Afghanistan. He has been ordered to kill any rebel insurgents who engage in anti-government violence. According to the principles of obedience that Milgram found, Vince will have more difficulty obeying orders when

A) everyone else in his troop is carrying out the orders given to them.
B) the victims are right in front of Vince versus 500 metres away.
C) Vince's commanding officer is beside him in the field.
D) his commanding officer is the top-ranked officer in Vince's division.