guaranty deposite啥时交

问题如下：

Futures exchanges and clearinghouses require members to provide margin in various situations to limit the risk that exchanges may develop through futures trading. Which of the following statements is true？

选项：

A.

Original margin requirements generally reflect the price volatility of futures contracts.

B.

Guaranty deposit is defined as the deposit that the clearing member must make by the start of the trading session.

C.

Variation margin is defined as the deposit that the clearing member must make when a trade is initiated.

D.

Original margin represents the deposit that the clearing member must maintain at the clearinghouses as long as it remains a member.

解释：

交易开始时缴纳的钱叫initial margin，因此B不对。

同理C也不对。Variation margin 是收到margin call补缴的钱。

成为会员时缴纳的钱叫garanty deposit，所以D也不对