Detailed Instructions: In this task, you will be presented with a question having multiple possible answers in Japanese language. And you should choose a most suitable option out of "A", "B", "C", "D", and "E" based on your commonsense knowledge.
Q: Question: 彼は何をするか誓わなければならなかった？ 
 Options: A 思う B 嘘ではない C うそをつかない D 義務感 E 正直な 
A:
E