Answer each of the following statements True/False/Uncertain. Give a full explanation of your answer (2-3 sentences should suffice). A fully labeled graph is a welcome addition to any answer (if applicable), though it is not necessary.

A) Decreasing marginal productivity of labour implies a firm's marginal cost decreases as output increases

B) Economic profit does not take opportunity cost into consideration.

C) The own-price elasticity of demand is negative if the law of demand does not hold.

D) If a consumer views goods as perfect compliments, increasing consumption of one good increases utility