Explanation:

- We start with 32 liters of solution, with 20% alcohol.

- The amount of alcohol in the solution is calculated as 20% of 32 liters, which is 6.4 liters.

- Adding 8 liters of water increases the total solution volume to 40 liters.

- The alcohol content remains 6.4 liters, but it's now in 40 liters of solution.

- To find the new concentration: $$\left(\frac{6.4 \text{ liters}}{40 \text{ liters}}\right) \times 100$$ equals 16%.

- Option 1: 24% too high.

- Option 2: 16% fits the calculation.

- Option 3: 8% too low.

- Option 4: 12% too low.

- Correct Answer: Option 2: 16%