问题如下：
A trader sells a put option on a stock with a strike price of USD 50 when the stock price is USD 51. The price of the option is USD 3. Under what circumstances does the trader make a profit? (Ignore the impact of discounting.)
选项：
解释：
The payoff is max(50 - ST,0). This is greater than the price paid when:
50 - ST > 3 or ST < 47
老师好。这个题是sell,所以是short put,求利润应该是p-(x-s)>0,所以s>47.请问我的理解哪里不对
