1. If the marginal rate of technical substitution (MR7S) is 1/3. then A) ilukes 3 units of labor to replace 1 unit of capital in the production process, such that output remains unchanged. B) labot is very productive relative to capital C) it takes 113 of a unit of capital to replace I unit of labor in the production process. such that output remains unchanged. D) the slope of the isoquant is very steep at the associated input combination E) both A and Care correct