Definition: In this task, you're given a statement and three sentences as choices. Your job is to determine which sentence can be inferred from the statement. Incorrect choices change the meaning in important ways or have details that are not mentioned in the statement. Indicate your answer as 1,2, or 3 corresponding to the choice number of the selected sentence.
Input: Statement: Certainly not. We all trooped out into the corridor, leaving the two doctors alone, and I heard the key turned in the lock behind us.  Choices:  1. The doctors conducted their work.  2. We stayed with the doctors.  3. We left the two doctors alone and locked the door. 

3