The answer is:
A. The incident demonstrates how violence is an ever-present threat for everyone.
D. The incident shows that while some are driven to cruelty by their terrible circumstances, others take great risks to show kindness.
During this part of the story Eliezer is brutally beaten by Idek, the Kapo, by no reason hence, Idek is prone to madness, and Eliezer just got in his way, Eliezer gets really hurt and the French girl to who he never speak before, tend to his wounds and conform him.