Choice A is the correct answer. Translate function notation to points.

1. Points: $(2, 3)$ and $(5, 9)$.
2. Formula: $m = \frac{9 - 3}{5 - 2}$.
3. Calculate: $m = \frac{6}{3} = 2$.

💡 Strategic Tip:$f(x) = y$ means the input is $x$ and the output is $y$.

Choice B is incorrect because it is the run. Choice C is incorrect because it is the rise. Choice D is incorrect because it flips rise and run.