Question

why did japanese soldiers kill so many civilians in nanjing, china?
commanders encouraged their soldiers to be as brutal as possible.
civilians attacked the soldiers first, and then the soldiers retaliated.
soldiers were inexperienced at fighting and panicked under pressure.
chinese forces were closing in, so the soldiers took desperate measures.

Explanation:

During the Nanjing Massacre, Japanese commanders encouraged brutal behavior among soldiers. There is no evidence for the other claims. Civilians did not attack first, soldiers were not inexperienced in a way that led to such mass - killing out of panic, and Chinese forces closing in was not the reason for the massacre.

Answer:

A. Commanders encouraged their soldiers to be as brutal as possible.