Solve for the constant that must be added to the given binomial in order to make it a perfect square trinomial. Show the perfect square trinomial, and factor it.
x² + 24x

• A. Constant: 12, Perfect Square Trinomial: x² + 24x + 12, Factored Form: (x + 12)²
• B. Constant: 256, Perfect Square Trinomial: x² + 24x + 256, Factored Form: (x + 16)²
• C. Constant: 144, Perfect Square Trinomial: x² + 24x + 144, Factored Form: (x + 12)²
• D. Constant: 12, Perfect Square Trinomial: x² + 24x + 12, Factored Form: (x + 6)²

Answer: (C)