A firm is employing 10 units of L and 5 units of K to produce 20 tables. L costs $1 per unit and K 0.5 per unit. For the quantities of inputs employed, MP . 2 and MP = 0.5. In this situation:
a) Output can be increased by using more K and less L, with no extra cost
b) Both inputs should be used in equal proportions
c) The firm is producing at its maximum
d) Output can be increased by using more L and less K, with no extra cost