Last month, the price of a couch increased by $\textbackslash$600$. During a sale this month, the couch was offered at a $25\textbackslash\%$ discount. John bought the couch at $\textbackslash$2250$ at the sale. What is the percentage decrease in the cost of the couch as compared to the original price of the couch before the discount? 
选项为:A:$6.66\textbackslash\%$  B:$5\textbackslash\%$  C:$6.25\textbackslash\%$  D:None of the above.  请回答其中一个选项.