(a) What kind of returns to scale does this production function exhibit? f (21 ,2?) = [min {21 ,322 H; o a. Constant returns to scale 0 b. Decreasing returns to scale 0 c. Increasing returns to scale 0 d. Cannot be determined (b) At (21 .22) = (4,6), the marginal product of zlis and the marginal product of 22 is