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 model simulates the size of the pool of exchangeable base cations in the soil. Choices: 1. The model simulates the size of the pool of base cations in the dirt in the desert. 2. The model simulates the size of the pool of base cations in the water 3. The model simulates the size of the pool of base cations in the dirt.

1