Two college roommates have each committed to donating to charity each week for the next year. The roommates\textquotesingle{} weekly incomes are independent of each other. Suppose the amount donated in a week by one roommate is approximately normal with mean $\textbackslash$$30 and standard deviation $\textbackslash$$10, and the amount donated  in a week by the other roommate is approximately normal with mean $\textbackslash$$60 and standard deviation $\textbackslash$$20. Which of the following is closest to the expected number of weeks in a 52-week year that their combined donation will exceed $\textbackslash$$120? 
选项为:A:0; the combined donation never exceeds $\textbackslash$$120 in a week  B:1 week  C:3 weeks  D:5 weeks  E:8 weeks  请回答其中一个选项.