The answer is; D
Solar cells usually convert solar energy into electricity which could later be reserved. The efficiency of solar cells is still low, compared to other sources, with a conversion rate of 15% - 22%. This reduces the attractiveness of solar cells as a competitive source of energy. This also makes this form of energy expensive due to its inefficiency.
I would say D! Purely because it is looking at the effects of humans (therefore related to topics more geographical).
Hope that helps. :)
One option for reducing air pollution is to cut back on major producer factories.
DNA<span> and </span>RNA,<span> are </span>made<span> from monomers known as nucleotides.</span>
