Brett owns a vacation rental condominium. For purposes of computing applicable rental expenses, which of the following is incorrect?

a) Brett used the house for one day but received a fair rental price. This is a day of rental use.

b) Brett spent a week between rentals repairing the property. This is a week of personal use.

c) Brett's son used the unit for one week free. This is personal use.

d) Only actual days for which a fair rental is received are days of rental use.