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: Perhaps Zarco knew precisely where he was heading, having learned of the existence of Madeira from a Castilian source. Choices: 1. Zarco pursued Madeira for the next decade. 2. Zarco learned of Madeira's existence from a Castilian. 3. Zarco was unaware of Madeira.

1