\textbf{A stationery store owner calculated the mean and median price of all types of pen: 5 and 3, respectively. He plans to have a 20\% off sale. What are the new mean and median of pens in that store?} 
选项为:A:\textbf{mean: 4; median: 2.4}  B:\textbf{mean: 5; median: 2.4}  C:\textbf{~mean: 4; median: 3}  D:\textbf{~mean: 5; median: 3}  E:\textbf{mean: 2.4; median: 4}  请回答其中一个选项.