Stephanie is a taxi driver. She rents her taxi for $300/week. She feels she can take in $120/day in fares. Let D be the number of days she drives her taxi in a week and T be the total earnings she expects after subtracting the rental charge.

a. Identify four ordered pairs (D,T).
b. Write an equation that gives T as a function of D.
c. What is the most she can earn in a year at this rate?