Company A charges $30 plus $0.40 per mile for a car rental. The total charge for m miles is given by f(m) = 30+0.4m. For a similar car, Company B charges $30 plus $0.30 per mile. The total charge for m miles isn't given by g(m)= 30+0.3m. Which best describes the transformation from the graph of f(m) to the graph of g(m)?
A. Translation up
B. Translation down
C. Rotation
D. Reflection