Suppose that the total profit in hundreds of dollars from selling x items is given by p(x)=5x^2-6x+8.

Complete parts A through D below.

A) Find the average rate of change of profit as x changes from 3 to 5.

B) Find the average rate of change of profit as x changes from 3 to 4.

C) Find and interpret the instantaneous rate of change of profit with respect to the number of items produced when x=3 .

D) Find the marginal profit at x=5.