Choice C is the correct answer. The base $1.08$ indicates the percentage growth rate.

1. Analyze Base: The growth factor is $b = 1.08$.
2. Find Rate: Since $b = 1 + r$, we have $1.08 = 1 + r$, so $r = 0.08$.
3. Convert to %: $0.08 = 8\%$.

💡 Strategic Tip: To find the percentage rate from the factor $1.XX$, just look at the decimal part $XX$.

Choice A is incorrect because the initial investment is 2500. Choice B is incorrect because exponential growth is by a percentage, not a fixed dollar amount. Choice D is incorrect because 108% growth would mean $b = 2.08$.