请教一下，有一道习题是这样写的：On the settlement date of a forward contract:

A. the short may be required to sell the asset

C. at least one party must make a cash payment to the other

正确答案是说的是A, 可是书上写的Forward contracts obligates one party to buy and the other to sell. 而不是A中写的是"may be"？ 请问老师这是为什么呢？ 还想请问，为什么C是错误的呢？

谢谢！！！

明白了！非常感谢！