31. In which of the following cases does the Constitution grant exclusive jurisdiction to federal courts?

a. A divorced couple in Montana cannot agree to share financial support of their
shared property.
b. A motorist in Florida is charged with reckless driving after running over a
fire hydrant.
c. The states of Missouri and Illinois are in dispute over water rights on the
Mississippi river.
d. A man from Ohio is accused of committing fraud in his hometown.