Consider a ski resort which uses capital K (mountains, ski lifts, lodges, etc.) and labor L (ski instructors, rental shop employees, kitchen staff, etc.) to accommodate q skiers per day according to the production function q = f(K,L). If the production function exhibits diminishing marginal returns to labor and capital, then which of the following statements is true?
a) As more labor is hired, the marginal product of labor decreases.
b) As more capital is used, the marginal product of capital decreases.
c) Both a) and b) are true.
d) Neither a) nor b) is true.