Complete the recursive case that can replace XXX in this function that calculates the factorial of the given number.

def factorial$($number$)$:

if number $==0$:

return $1$

else:

XXX

print$($factorial$(4))$

a$.$

return number$*($number$-1)$

b$.$

Multiple of these work

c$.$

return $($number$-1)*($number$-2)$

d$.$

None of these work

e$.$

return number$*$factorial$($number$-1)$

f$.$

return factorial$($number$)*$factorial$($number$-1)$