Choice A is the correct answer. Tripling means $b=3$.

1. Initial: Starts at 10, so $a=10$.
2. Factor: Triples means multiplying by 3, so $b=3$.
3. Equation: $y = 10(3)^x$.

💡 Strategic Tip: "Triples" is a keyword for exponential growth with base 3.

Choice B is incorrect because it swaps start and factor. Choice C is incorrect because$1/3$ is decay.