①$$3\times 4\times 3\times 2\times 1=72$$ ,  ②$$2\times 4\times 3\times 2\times 1=48$$ . 
Four students asked their teacher, Mr Carter, to line up with them to take a picture.  ① If Mr Carter does not want to stand on either end, how many different ways can they line up for the picture?  ② If Mr Carter insists on standing on one of the $2$ ends, how many different ways can they line up for the picture? 
(A) $72$ , $24$ 
(B) $96$ , $24$ 
(C) $72$ , $48$ 
(D) $96$ , $48$ 