Choice A is the correct answer. Calculate long-term growth.

1. Formula: $A = 50000(1.06)^{30}$.
2. Calculate: $(1.06)^{30} \approx 5.7435$, so $A \approx 287,175$.
3. Rule of 72: Doubling time ≈ $\frac{72}{6} = 12$ years. In 30 years ≈ 2.5 doublings → $50k \times 2^{2.5} \approx 283k$ ✓.

💡 Strategic Tip: Long-term exponential growth can produce dramatic results.

Choice B is incorrect because this only quadruples the principal. Choice C is incorrect because this only triples the principal. Choice D is incorrect because the calculation doesn't match.