17. The factorial of an integer is the product of that integer multiplied by all the positive non-zero integers less than that integer. So, 5! (! is the mathematical symbol for factorial) is 5 * 4 * 3*2*1. 4! is 4*3*2*1, so 5! could be written as 5*4!. So a recursive definition of factorial is n! is n*(n-1)!, as long as n >1. 1! is 1. What is the recursive call for this function (fact)?

a. fact(n)*n;
b. fact(n-1)*n;
c. (n-1)*fact(n)
d. fact(n-2)*(n-1)

b. fact(n-1)*n;