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: These uncertainties can be reduced by careful consideration of the differences in the health risk or air pollution commodity and the study populations in the underlying economic literature versus the context of benefits conferred by the Clear Skies Act. Choices: 1. The risk of air pollution is the most important type of pollution which should be carefully considered.  2. There is no way to reduce these uncertainties at this time. 3. Careful observation and studying of health risks by air pollution can help ease uncertainties. 

1