A jacket was on sale. The original price was ＄$$180$$, and Peter bought it at ＄$$135$$. What was the discount rate? 
选项为:A:$$135\textbackslash\%$$  B:$$180\textbackslash\%$$  C:$$75\textbackslash\%$$  D:$$25\textbackslash\%$$  请回答其中一个选项.