Show, with induction, that the inequality n^2 + 2n < 3^n holds for all natural numbers n greater than or equal to 2. Which of the following options correctly completes the statement?
A) n^2 + 2n > 3^n
B) n^2 + 2n = 3^n
C) n^2 + 2n <= 3^n
D) n^2 + 2n >= 3^n
