NO.PZ2016031201000007
问题如下：
An interest rate swap is a derivative contract in which:
选项：
A. two parties agree to exchange a series of cash flows.
B. the credit seller provides protection to the credit buyer.
C. the buyer has the right to purchase the underlying from the seller.
解释：
A is correct.
An interest rate swap is defined as a derivative in which two parties agree to exchange a series of cash flows: One set of cash flows is variable, and the other set can be variable or fixed.
B is incorrect because a credit derivative is a derivative contract in which the credit protection seller provides protection to the credit protection buyer. C is incorrect because a call option gives the buyer the right to purchase the underlying from the seller.
b选项怎么翻译和理解