UNUN Peacekeeping Efforts Sometimes Fail

U.N.UN peacekeeping efforts sometimes fail. Under what circumstances are they most likely to succeed?

A) When states or groups are determined to go to war
B) When states or groups hope to avoid conflict but might be afraid that others will take advantage of them
C) When there is ethnic cleansing going on and the stakes are very high
D) When there is civil war based on religious tensions