Understanding the least-cost rule bob runs a surfing school on the north shore of oahu. he has two inputs: surfboards, which he rents from a local shop for $12 per day, and surfing instructors, whom he hires for $40 per day. bob has figured out that the marginal physical product (mpp) of the last instructor hired is 24 lessons, and the mpp of the last board used is 6 lessons.

which of the following statements is correct?
a. any of these answers may be right, depending on the price of a lesson.
b. bob could lower his costs without reducing his output if he employed more instructors and used fewer surfboards.
c. bob currently employs a cost-minimizing combination of surfboards and instructors.
d. bob could lower his costs without reducing his output if he employed fewer instructors and used more surfb