At the point of diminishing returns in a shaving cream factory,
(a) the average product of the variable input is zero.
(b) the marginal product of the variable input is zero.
(c) the marginal product of the variable input is at a maximum.
(d) the average product of the variable input is at a maximum.
(a) the average product of the variable input is zero.
(b) the marginal product of the variable input is zero.
(c) the marginal product of the variable input is at a maximum.
(d) the average product of the variable input is at a maximum.