4) A

The argument made in the text is that “nuclear power stations…would create tens of thousands of tons of lethal, high-level radioactive waste” and that “the expansion of all nuclear power production shout therefore be stopped and existing plants shut down.”

We need to find a weakness in the argument.

A – Correct

A is the answer as it suggests that there are solutions to the nuclear waste problem and that safety is taken into consideration.

B – Wrong

This actually strengthens the argument as it suggests that the significance of nuclear power will decrease in the future.

C  – Wrong

C is wrong because it makes an unnecessary comparison between wind power and nuclear power. So C is irrelevant to the question.

D – Wrong

We do not know whether 2.5 billion tonnes of carbon dioxide is a lot or a small amount. So we cannot determine whether this weakens or strengthens the argument.