The clearing process of OTC derivatives is the process by which payment obligations between two or more parties are computed and netted, and the settlement is the process by which the contract obligations are fulfilled. Clearing is the first step in the process, where the payment obligations of each party are calculated and netted against each other. This process involves the calculation of the net amount that each party owes to the other, taking into account all the transactions that have taken place between them. Once the net obligations have been determined, the next step is settlement. Settlement is the process by which these obligations are fulfilled. This involves the actual exchange of cash or assets between the parties, in accordance with the net obligations that were determined during the clearing process. Therefore, the statement in choice B accurately describes the difference between the clearing and settlement processes of OTC derivatives.

Choice A is incorrect. The statement has reversed the definitions of clearing and settlement. Clearing is the process by which payment obligations between two or more parties are computed and netted, not settlement.

Choice C is incorrect. While it's true that members are required to post cash and assets against their open positions during the clearing process, this statement does not accurately define what clearing entails in its entirety. Clearing involves computing and netting payment obligations between parties.