Answer: c. Large-scale oil spills are damaging to water quality, aquatic life, and bird populations.
Large- scale oil spills will deposit oil in the layers of water body due to which oil will prevent oxygen supply from air inside the water body. Lack of oxygen in the water body will affect the aquatic life form as oxygen is necessary for their respiration. This will result in mortality of aquatic life forms : flora and fauna. Also, the oil will be consumed by these aquatic animals which may remain undigested in their bodies. This results in a phenomena called biomagnification. In biomagnification toxic chemicals are accumulated in the living organisms as one organism is fed by the other organism, these toxic chemicals remains undigested in their body and further leads to their mortality. The oil is consumed from the water, transferred from lower trophic level e.g small fish to higher trophic level e.g mammals. The fishes may be eaten up by bird populations. This will result in increase in mortality rate in the bird population. Therefore, overall environment will be affected by a large-scale oil spill.