Answer:
b.) methane and long branches alkanes
Step-by-step explanation:
Petroleum or crude oil is a fossil fuel formed by the decomposition of organisms buried under the earth's surface and subjected to intense pressure and temperature. It is composed of a mixture of hydrocarbons which include paraffins (linear and branched alkanes), naphthenes (cyclic alkanes) and other aromatic compounds.
However, petroleum is predominantly consists of paraffins which have the general formula CnH2n+2 and include methane and other long branched alkanes.