I believe it is amino acids?
Answer:
London smog results from a high concentration of sulfur oxides in the air and is caused by the use of sulfur-bearing fossil fuels, particularly coal. This type of smog is aggravated by dampness and a high concentration of delayed particulate matter in the air.
Explanation:
So, the answer would be B or D.
But, it is most likely B due to dampness.
Igneous - A rock formed by the cooling and crystallization of magma (molten rock) at or below the Earth's surface. Sedimentary - A rock formed as a result of the weathering process, either by compaction and cementation of rock mineral fragments, or the precipitation of dissolved minerals.