Sam wants to use two kinds of sugar water with concentrations of $$5\textbackslash\%$$ and $$20\textbackslash\%$$ to make a sugar water of $$300$$g with a concentration of $$15\textbackslash\%$$. He correctly calculated the required ratio of the two solutions, but reversed the two bottles of sugar water when preparing them. The actual concentration of the wrongly mixed sugar water is~\uline{~~~~~~~~~~}~$$\textbackslash\%$$. 
选项为:A:$$8$$  B:$$10$$  C:$$12.5$$  D:$$15$$  E:None of the above  请回答其中一个选项.