（2018 YMO, Grade 3, Question\#4）  According to this set of number, $$3$$，$$1$$，$$2$$，$$3$$，$$1$$，$$2$$，$$\cdots \cdots $$, what will be the $$53$$\textsuperscript{rd} one? ．  有一列数：$$3$$，$$1$$，$$2$$，$$3$$，$$1$$，$$2$$，$$\cdots \cdots $$那么第$$53$$个数是． 
选项为:A:$$3$$  B:$$1$$  C:$$2$$  请回答其中一个选项.