4. A group of friends rents a boat to spend an afternoon on a lake. The boat rental has a flat fee of $180 for up to three hours and $50 per hour for each additional hour. The first four passengers are included in this cost, but $20 is charged for each additional passenger. Write a linear equation to describe this situation, where c is the total cost of the rental, h is each additional hour (over 3) and p is each additional passenger (over 4). options:
A. c = 230h + 20p
B. c + 180 = 50h + 20p
C. c = 180 + h + p
D. c = 180 + 50h + 20p