Definition: In this task, you're given a statement and three sentences as choices. Your job is to determine the neutral choice based on your inference from the statement and your commonsense knowledge. The neutral choice is a sentence that neither agrees nor disagrees with the statement. Indicate your answer as '1', '2', or '3', corresponding to the choice number of the selected sentence. If sentence X agrees with sentence Y, one's correctness follows from the other one. If sentence X disagrees with sentence Y, they can not be correct at the same time.
Input: Statement: the costs and difficulties of the ED setting, the relative efficacy and cost of booster sessions is another important issue deserving further research. Choices: 1. Booster sessions are estimated to cost over ten million dollars. 2. Another issue that needs to be looked into is the cost of booster sessions. 3. The cost of booster sessions is negligible, so it can be ignored.

1