The manager of Paul's fruit and vegetable store is considering the purchase of a new seedless watermelon from a wholesale distributor. Since this seedless watermelon costs $4, will sell for $7, and is highly perishable, he only expects to sell between 6 and 9 of them.

What is the opportunity loss for purchasing 9 watermelons when the demand is for seven?

a. 8

b. 4

c. 12

d. 0