Choice Bhoice C is the correct answer.

1. Start with the equation: $\frac{x}{2} - 5 = 4$
2. Add 5 to both sides: $\frac{x}{2} = 4 + 5$
3. Simplify: $\frac{x}{2} = 9$
4. Multiply both sides by 2: $x = 9 \times 2$
5. Simplify: $x = 18$
6. Verify: $\frac{18}{2} - 5 = 9 - 5 = 4$ ✓

Choice Bhoice C is incorrect because this results from subtracting 5 from 4: $-1$, then multiplying by 2: $-2$. Wrong inverse operation.

Choice Bhoice D is incorrect because this is the value of $\frac{x}{2}$. You must multiply by 2.

Choice Bhoice D is incorrect because this results from dividing 9 by 2: $4.5$. We need to multiply.