Several students are singing in a line. Amy is the fourth one from the left. From the right, Amy is the fourth too. How many students are singing? (adapted from $$2019$$ Math kangaroo Problems, Level $$1-2$$, Question \#$$5$$) 
选项为:A:$5$  B:$6$  C:$7$  D:$8$  E:$9$  请回答其中一个选项.