What type of organic compound contains only carbon and hydrogen?

The correct choice identifies hydrocarbons as organic compounds consisting solely of carbon and hydrogen atoms. This definition is foundational in organic chemistry, where hydrocarbons serve as the simplest type of organic molecules. They can vary in structure, including linear chains, branched forms, and cyclic structures, and can be saturated (single bonds only) or unsaturated (one or more double or triple bonds).

Other options like alcohol, carbohydrate, and amine contain additional elements such as oxygen or nitrogen. For instance, alcohols include a hydroxyl (-OH) group, carbohydrates typically contain carbon, hydrogen, and oxygen in a specific ratio, and amines consist of nitrogen along with carbon and hydrogen. Therefore, hydrocarbons stand out as unique due to their exclusive composition of carbon and hydrogen, making them the correct answer to the question.