NO.PZ2023091802000124
问题如下：
Of the following options, which one does not benefit from an increase in the stock price when the current stock price is $100 and the barrier has not yet been crossed:
选项：
A.A down-and-out call with out barrier at $90 and strike at $110
B.A down-and-in call with in barrier at $90 and strike at $110
C.An up-and-in put with barrier at $110 and strike at $100
D.An up-and-in call with barrier at $110 and strike at $100
解释：
A down-and-out call where the barrier has not been touched is still
alive and hence benefits from an increase in S, so a. is incorrect. A
down-and-in call only comes alive when the barrier is touched, so an increase
in S brings it away from the barrier. This is not favorable, so b. is
correct. An up-and-in put would benefit from an increase in S as this
brings it closer to the barrier of $110, so c. is not correct. Finally, an
up-and-in call would also benefit if S gets closer to the barrier.
当是uo and in 的put option 的时候，如果是stock涨到110了，然后我就进入了这个option，然后我的benefit是X-S，但是我的X是100，那不就是还是负数的benefit了。
