Choice A is the correct answer. Find the slope from the intercepts.

1. Points: $(0, 3)$ and $(-3, 0)$.
2. Slope: $m = \frac{0 - 3}{-3 - 0} = \frac{-3}{-3} = 1$.
3. Y-intercept: $b = 3$.
4. Equation: $y = 1x + 3$, or $y = x + 3$.

💡 Strategic Tip: A line crossing at $(a, 0)$ and $(0, a)$ always has a slope of 1 if signs match, or -1 if signs differ.

Choice B is incorrect because it has a negative slope. Choice C is incorrect because it has the wrong y-intercept. Choice D is incorrect because it has the wrong slope.