Which of the following statements is false?

A. Marking to market of futures contracts is the process of realizing gains and losses each day as the futures contract changes in price.

B. European-style options are options that may only be exercised at maturity.

C. A clearinghouse backs the buyer's and seller's position in a forward contract.

D. In a futures contract, if funds in the margin account fall below the maintenance margin requirement, a margin call is issued.