Please answer the questions below and provide explanation:

1) Which of the following experiments will yield observations that would allow one to calculate the marginal physical product of labor?

increase the number of workers on an assembly line and record the change in output

a. increase the number of lumberjacks with chain saws and observe the change in output of cut trees

b. increase the number of workers on an assembly line and record the change in output

c. both a and b are correct

d. neither a nor b are correct

2) Total profit

a. is the difference between sales revenue and costs

b. maximization is always the goal of every firm

c. is always defined the same by both economists and accountants

d. is maximized when sales are maximized

3) Whenever average cost exceeds marginal cost,

a. average cost is rising.

b. average cost is falling.

c. marginal cost is rising.

d. marginal cost is falling.

4) The result that perfectly competitive firms produce at the lowest per-unit cost is derived from the assumption of

a. homogeneous products

b. few sellers

c. firms facing horizontal demand curves

d. free entry and exit