Hello there!
Your question asks why Appeasement was a popular policy for European leaders.
Answer: B.) wanted to avoid another war.
The reason why answer choice "B.) wanted to avoid another war" would be the correct answer is because European leaders used the Appeasement policy in order to avoid having other conflicts with other leaders. At the time when European Leaders used the Appeasement policy, there was a strong political and public aspiration to have "peace at any price." This was because of the Great War, took place in France and Britain. There's another reason why they used the Appeasement policy. The other reason why they used the Appeasement policy is because the leaders countries were not ready for another war. The countries militaries were not close to being ready for another war, in which if they get into a war, they would probably lose it. Wars cost a lot of money and lives, and the countries leaders can't risk going through that. This is the reason why many European leaders used the Appeasement policy; just to keep away from conflicts that would start a war between other leaders.
I hope this helps!
Best regards, MasterInvestor