问题如下：
Which of the following statement about American option is most accurate?
选项：
A.Dividends are not the reason to exercise American option early.
B.American calls should be exercised early only if the underlying pays dividends, but American puts would not.
C.American puts should be exercised early only if the underlying pays dividends, but American calls would not.
解释：
B is correct. Dividends encourage early exercise for American calls, not puts.
为什么分红会使美式期权提前行权？
