Choice A is the correct answer. Determine the number of half-lives.

1. Remaining: $\frac{25}{200} = \frac{1}{8} = (\frac{1}{2})^3$.
2. Half-lives: 3 half-lives have occurred.
3. Time: $3 \times 88 = 264$ years.

💡 Strategic Tip:$\frac{1}{8}$ means 3 halvings: $50\% \to 25\% \to 12.5\%$.

Choice B is incorrect because this is 2 half-lives (would leave 50 grams). Choice C is incorrect because this is 1 half-life (would leave 100 grams). Choice D is incorrect because this is 4 half-lives (would leave 12.5 grams).