Answer to Question 1
D
Answer to Question 2
Crude oil spills tend to be larger in volume and frequency than the refined oil spills. The crude oil spills are not as harmful though.
Many crude oil components are unable to dissolve quickly in eater. The components that are able to dissolve quickly are harmful to juvenile organisms. The insoluble components create a sticky, thick layer on the surface. This prevents the free diffusion of gasses, reduces the amount of sunlight available, and can clog feeding structures in organisms. Overall, crude oil is not considered to be highly toxic, and it is biodegradable.
Refined oil spills are much more dangerous. The heavier components are removed from the oil or broken down during the refining process. Also, deadly components are added to the oil through this process. The heavy tar remains volatile after the components evaporate. This tar gets dropped to the seafloor, incorporated into sediments, or even ingested by organisms in the benthic communities.
