Choice Bhoice D is the correct answer.

1. Start with the equation: $\frac{x}{3} + 5 = 9$
2. Subtract 5 from both sides: $\frac{x}{3} = 9 - 5$
3. Simplify: $\frac{x}{3} = 4$
4. Multiply both sides by 3: $x = 4 \times 3$
5. Simplify: $x = 12$
6. Verify: $\frac{12}{3} + 5 = 4 + 5 = 9$ ✓

Choice Bhoice C is incorrect because this results from adding 5 to 9: $14$, then $14 \times 3 = 42$. Wrong inverse operation.

Choice Bhoice D is incorrect because this is the value of $\frac{x}{3}$. You must multiply by 3.

Choice Bhoice C is incorrect because this results from dividing 4 by 3: $1.33$. We need to multiply.