\textbf{Daniel is learning that five pennies spread out on his desk are the same number of coins as five pennies in a pile. According to Piaget, how old is Daniel likely to be?} 
选项为:A:1~\textbf{year}  B:2~\textbf{years}  C:\textbf{4 years}  D:\textbf{8 years}  E:\textbf{13 years}  请回答其中一个选项.