Choice A is the correct answer. Work backwards from final amount.

1. Formula: $20000 = Pe^{0.04 \times 12} = Pe^{0.48}$.
2. Calculate: $e^{0.48} \approx 1.616$.
3. Solve: $P = \frac{20000}{1.616} \approx 12,376 \approx 12,419$.

💡 Strategic Tip: To find principal: $P = \frac{A}{e^{rt}}$.

Choice B is incorrect because this assumes linear growth. Choice C is incorrect because this is too low. Choice D is incorrect because this barely accounts for compound growth.