Choice A is the correct answer. Hypotenuse length.

1. Intercepts: $(4, 0)$ and $(0, 3)$.
2. Distance: $\sqrt{(4-0)^2 + (0-3)^2} = \sqrt{16 + 9} = \sqrt{25} = 5$.

💡 Strategic Tip: It's a 3-4-5 right triangle.

Choice B is incorrect.Choice C is incorrect.Choice D is incorrect.