Solve the Equation $$| 3 x - 21 | + 15 = 21$$

Solve the equation. $$| 3 x - 21 | + 15 = 21$$

A) x = -5, x = 9
B) x = 9
C) x = 5, x = 9
D) x = 5
E) x = -5, x = -9