Choice A is the correct answer. Analyze the initial value and direction.

1. Initial Value: When $x=0$, $y = 3(0.8)^0 = 3$, so y-intercept is 3.
2. Base: $0.8 < 1$ means the function is decaying (decreasing).
3. Match: Graph with y-intercept 3 and decreasing curve.

💡 Strategic Tip: If $b < 1$, the graph decreases (decay). If $b > 1$, it increases (growth).

Choice B is incorrect because the base 0.8 < 1 means decay, not growth. Choice C is incorrect because the y-intercept is 3, not 0.8. Choice D is incorrect because both the y-intercept and direction are wrong.