Question

Oil spills reduce _____________ supplies within the water environment.
A) Carbon dioxide
B) Oxygen
C) Nitrogen
D) None of these

Answer 1

Hint: Oil spill is the leakage of petroleum onto the surface of a large body of water. Refer to the effects of oil spills on marine and aquatic life. Crude oil ruins the insulating and waterproofing properties of fur and feathers, and thus oil-coated birds and marine mammals die from hypothermia.

Complete answer:
Oil spill is the leakage of liquid petroleum onto the surface of a large body of water. Oil spills may be due to release of crude oil from tankers, offshore platforms, wells and drilling rigs.
Crude oil ruins the insulating and waterproofing properties of fur and feathers, and thus oil-coated birds and marine mammals die from hypothermia. Oil spills on ocean surfaces are quite harmful for many forms of aquatic life. Oil spills prevent sufficient amounts of sunlight from penetrating the surface and also reduces the amount or level of dissolved oxygen in water bodies. Moreover, ingested oil can be toxic to animals and their habitat. One of the industries which is most affected by oil spills is the fishing industry. Most of the oil spills are frequently followed by the immediate suspension of commercial fishing.
Thus, among all the options, oxygen is the correct because oil spills reduce dissolved oxygen level in the water environment.

Hence, option B is the answer.

Note:
Cleanup and recovery from oil spills is difficult and it depends upon many factors, including the type of oil spilled, the temperature of the water (affecting evaporation and biodegradation), and the types of shorelines and beaches involved.