Answer: option A and B are the two options making sense here. For option B, if the light is from an incandescent light bulbs.
Explanation:
Starting from option B, that is turning on a light. Here, we are going to make assumption that the question is talking about light from incandescent light bulbs. Turning on a light from an incandescent light bulbs actually results in air pollution. Incandescent light bulbs emit Carbondioxide into the environment which can have important effect on global climate.
For option A, that is, investing in gold coins. In the United States of America, the price of Gold has been stated as a currency value. Investment in gold is a good way of hedging properties, and this is done by many countries. Until recent times gold has been used by many countries as relative standard for currency equivalents. The central banks of many countries influence the price of gold.
