Why do ralph piggy and samneric that they left jack feast early
lord of the flies

In the lord of flies, when Samneric show up, all four boys pretend they left the feast early. The thing is that all four appear nervous as they discuss where they were the previous night, trying to avoid the subject of Simon's murder. All insist that they left early, right after the feast.

But, the answer is a B.simple sentence, because i just got it right after choosing the wrong one.