Help me out with this problem:

A family consisting of one mother, one father, two daughters and a son is taking a road trip in a sedan. The sedan has two front seats and three back seats. If one of the parents must drive and the two daughters refuse to sit next to each other, how many possible seating arrangements are there?


28

32

48

60

120


Let me know the method. I thought n!/(n-r), but not sure.