$$4 \times 3 \times 1 \times 2 \times 1 = 24$$. 
Today is Amy\textquotesingle s birthday! She takes photos with her four close friends. All of them stand in a line and they make Amy stand in the middle. There are~\uline{~~~~~~~~~~}~different ways for them to form the line. 
[A] $$12$$ 
[B] $$16$$ 
[C] $$20$$ 
[D] $$24$$ 
[E] $$36$$ 