Joey's Lawncutting Service Rents Office Space from Joey's Dad for $300

Multiple Choice

Joey's Lawncutting Service rents office space from Joey's dad for $300 per month.Joey's dad is thinking of increasing the rent to $400 per month.As a result Joey's marginal cost of cutting grass will

A) increase by $100 divided by the amount of grass cut.
B) increase by $100.
C) decrease by $100.
D) not change.