A) 20! is multiple of 15, while 17 is not. Therefore, n= 20! + 17 is NOT divisible by 15. B) 20! is multiple of 17, therefore n= 20! + 17 IS divisible by 17. C) 20! is multiple of 19, while 17 is not. Therefore, n= 20! + 17 is NOT divisible by 19. Now you are in position to make all selections/decisions.