From which sources are hydrocarbon solvents obtained?

Hydrocarbon solvents are primarily derived from petroleum or coal tar sources. These solvents consist of various hydrocarbons – organic compounds made up entirely of hydrogen and carbon. Petroleum, which is refined to create fuels and other chemical products, contains a mixture of these hydrocarbons, making it a rich source of hydrocarbon solvents. Coal tar, a byproduct of the carbonization of coal, also contains numerous aromatic hydrocarbons that can be used to produce solvents.

The other options represent different types of materials that do not yield hydrocarbon solvents. Wood products do not contain hydrocarbons in a way that would create solvents; instead, they are primarily composed of cellulose, hemicellulose, and lignin. Cotton fibers, derived from the cotton plant, are predominantly cellulose and are not sources of hydrocarbon solvents either. Vegetable oils, although organic and containing hydrocarbons, are primarily triglycerides and do not qualify as hydrocarbon solvents in the context of industrial applications. Therefore, petroleum and coal tar are the correct and primary sources for hydrocarbon solvents.