Choice A is the correct answer. Use the compound interest formula.

1. Formula: $A = P(1 + r)^t$ where $P = 5000$, $r = 0.06$, $t = 3$.
2. Calculate: $A = 5000(1.06)^3 = 5000(1.191016) \approx 5955.08$.
3. Result: After 3 years, the investment is worth $5,955.08.

💡 Strategic Tip: For annual compounding, use $A = P(1 + r)^t$ directly.

Choice B is incorrect because this assumes simple interest, not compound. Choice C is incorrect because this only adds one year of interest. Choice D is incorrect because this assumes 20% total growth, not compound.