If the long-term impacts of a new chemical technology are uncertain, what would the precautionary principle suggest?

Correct answer: Limited use, strict testing and monitoring

Where long-term effects are uncertain and potentially serious, a precautionary approach would limit exposure while requiring controlled testing, independent risk assessment, safety standards and continued monitoring. Evidence from monitoring can guide later expansion, modification or withdrawal. Immediate widespread use would transfer unknown risks to people and ecosystems, while ignoring warnings or focusing only on profit fails to address possible irreversible harm. Hence A is correct.