Choice Dhoice C is the correct answer. When the variable is in a fraction, we multiply to isolate it.

1. Start with the equation: $\frac{x}{6} = 12$
2. Multiply both sides by 6: $x = 12 \times 6$
3. Calculate: $x = 72$
4. Verify: $\frac{72}{6} = 12$ ✓

💡 Strategy: For $\frac{x}{a} = b$, always multiply: $x = ab$.

Choice Dhoice A is incorrect because this results from dividing 12 by 6 instead of multiplying: $\frac{12}{6} = 2$. This divides when we should multiply.

Choice Dhoice C is incorrect because this comes from adding: $12 + 6 = 18$. Addition is not the inverse of division.

Choice Dhoice D is incorrect because this results from dividing in the opposite direction: $\frac{6}{12} = 0.5$. This is the reciprocal of Choice Dhoice A.