E the amount of output cannot be varied 7. If the marginal rate of technical substitution (MR7S) is 1/3. then A) it takes 3 units of labor to replace I unit of capital in the production process, such that output remains unchanged. Bi labor is very productive relative to capital. C) it takes 1/3 of a unit of capital to replace I unit of labor in the production process. such that output remains unchanged. Dp the slope of the isoquant is very steep at the associated input combination Ey both A and C are correct