In how many ways can 16 people be seated:
A. In a row, if 4 of the 16 do not want to sit next to one another
B. In a row, if 3 of the 16 must be seated next to one another
C. In a circle, if 3 of the 16 must be seated next to one another
D. In a circle, if 4 of the 16 do not want to...