Which elements are present in a hydrocarbon compound?

Hydrocarbon compounds are defined as organic molecules that consist exclusively of two elements: hydrogen and carbon. These compounds are fundamental in organic chemistry and serve as the primary framework for a vast array of organic molecules, including fuels, plastics, and many other chemicals.

The presence of hydrogen is crucial, as it makes up a significant portion of the molecular structure, while carbon acts as a versatile backbone that allows for the formation of complex structures through various bonding arrangements. As such, when identifying a hydrocarbon compound, recognizing that it includes only hydrogen and carbon is essential.

The other combinations mentioned in the choices include elements that are not part of the definition of hydrocarbons. Therefore, the clarity of the relationship between only hydrogen and carbon helps reinforce their vital role in the structure and classification of hydrocarbons in organic chemistry.