Answer:
A) charged any ticket price above $0 for the three remaining seats.
Explanation:
Seats on a bus are either used or not, and like any other service, they cannot be stocked. That means that the 3 unused seats cannot be added to another trip, the maximum number of seats that can be sold will remain at 50.
It doesn't matter at what price the company sells the 3 remaining seats, as long as it is above $0, it will increase its profits.