Choice A is the correct answer. Set $y=0$.

1. Substitute: $0 = \frac{1}{2}x - 3$.
2. Add 3: $3 = \frac{1}{2}x$.
3. Multiply by 2: $6 = x$.

💡 Strategic Tip: To clear the fraction, multiply the entire equation by the denominator.

Choice B is incorrect because it is the y-intercept. Choice C is incorrect because it misses the multiplication step. Choice D is incorrect because of sign error.