Explain how the clearinghouse would record the following:

a. Mr. A buys a September wheat futures contract from Ms. B for \(\$ 4.00 /\) bu. on July 20.

b. Mr. D buys a September wheat futures contract from Mr. E for \(\$ 3.95\) on July 25.

c. Ms. B buys a September wheat futures contract from Mr. D for \(\$ 4.01\) on July 30.

d. Mr. E buys a September wheat futures contract from Mr. A for \(\$ 4.06\) on August 3.

Show the clearinghouse's payments and receipts needed to close each position.