Definition: In this task, you're given a statement, and three sentences as choices. Your job is to determine which sentence clearly disagrees with the statement. Indicate your answer as '1', '2', or '3' corresponding to the choice number of the selected sentence.
Input: Statement: He was engaged in wondering how Mr. Brown had discovered his identity. Choices:  1. Mr. Brown discovered an identity. 2. He didn't care if Mr. Brown discovered his identity. 3. Mr. Brown was a keen observer to figure out his identity.

2