Figure 30-1 -Refer to Figure 30-1. Which of the Following Would Cause

Figure 30-1
-Refer to Figure 30-1. Which of the following would cause the change depicted in the figure above?

A) U.S. productivity rises relative to European productivity.
B) Europeans decrease their preferences for U.S. goods relative to European goods.
C) The European Union increases its quotas on French wine.
D) an increase in the price level of U.S. goods relative to European goods