问题如下：
Sam, a junior analyst, made following statements about options, which is(are) correct?
Statement 1: American options can be exercised at any time up to the expiration date.
Statement 2: The maximum gain for the seller of an put option is the premium, while the potential loss is infinite.
选项：
A.Statement 1.
B.Statement 2.
C.Both statement 1 and statement 2.
D.Neither statement 1 nor statement 2.
解释：
A is correct.
考点：Basic Characteristics of Option Contract
解析：美式期权在到期前任意时间点都可以行权，statement 1 正确。卖出看跌期权最大收益是期权费，最大损失是标的物资产价格降为0时，所以损失有限。statement 2 不正确。
油价能跌为负之后statement 2还算错吗😂
