Lily\textquotesingle s family used $$21$$ tons of water in the first two months, and an average of $$31$$ tons of water on the remaining three tests. The average tons of water for the five months was~\uline{~~~~~~~~~~}~. 
选项为:A:$$120$$  B:$$22$$  C:$$23$$  D:$$27$$  E:$$25$$  请回答其中一个选项.