Suppose on Monday June 1, you long and I short the futures contract on 1000 units of commodity, for December delivery. We enter the positions when the futures price is $15 per unit. We are required to post margins equal to 12% of the contract amount. On Tuesday June 2, the December contract settles at $15.75. Between Monday and Tuesday, my return will be what percentage?

a. -4.2%

b. 50%

c. -42%

d. 5%