Answer:
The supply curve for the euro shifts to the right
Explanation:
From the example above, United States is the producer of the grain. So, the payment that needed to be done to complete the transaction will most likely use Dollar.
As a result, the demand for the Dollar will increase. This cause the demand curve to shift to the right.
An increase in demand because of the transaction will the value of dollars and weaken the value of Euro. As a result, the supply curve for the Euro will most likely shifted to the left, not the right.