Please help explain how this impacts the IS curve (or cannot):

Latin America is a major export market for the US. Following the 1994 Mexican crisis, the real incomes of Latin American countries temporarily declined. What impact must this event have had on the IS curve of the US economy?

a.The IS curve must have shifted to the left.

b.The IS curve could not have been affected.

c.The IS curve must have shifted to the right.

d.The impact on the IS curve cannot be predicted.