What two conditions must exist for federal courts to have diversity jurisdiction?

a. an individual is bringing suit against a corporation and the amount in dispute exceeds $75,000

b. the plaintiff and defendant are from the same family and the amount in dispute exeeds $50,000.

c. the case has been tried in two different states with two different outcomes and the amount in dispute exceeds $50,000.

d. the plaintiff and defendant are citizens of different states and the amount in dispute exceeds $75,000.