If f(x) = (nⁿ * n²ⁿ * 5n) * (n! * 5n), then g(x) is equal to:
(a) n! * n² * 5²n+1)
(b) n²n+1 * n! * 5²ⁿ
(c) n³ⁿ * n! * 5²ⁿ
(d) nⁿ * n! * 5²n+1