On March 1, the spot price of a commodity is $20 and the July futures price is $19. On June 1, the spot price is $21, and the July futures price is $23.50. A company entered a futures contract on March 1 to hedge the purchase of the commodity on June 1. It closed out its position on June 1. What is the effective price paid by the company for the commodity? a. $ 17.50 b. $ 16.50 c. $ 25.50 d. $ -21.50