The correct answer is A. Were finally found
Step-by-step explanation:
In sentences, the predicate is the section that follows the subject or agent of the sentence and includes the verb and in most cases other words that complete the idea of it. In the case of the sentence presented "All except for Jesse and his brother were finally found" the subject is "All except for Jesse and his brother" because this describes the agent and therefore the predicate is "were finally found" as this is placed after the subject, contains the verb "were found" and the word "finally" that complete the idea in the sentence.