Final answer:
Calcium Oxide (CaO) is not an organic compound because it is an ionic compound without a carbon-based structure, which is a defining characteristic of organic compounds.
Step-by-step explanation:
The compound that is not an organic compound among the given options is (c) CaO, which stands for Calcium Oxide. Organic compounds are primarily made up of carbon atoms bonded to hydrogen and sometimes include elements such as oxygen, nitrogen, sulfur, and phosphorus. However, they are characterized by their carbon-based structure and covalent bonding. Calcium oxide does not fit this definition as it is an ionic compound consisting of calcium and oxygen ions and lacks a carbon-based structure, thus classifying it as an inorganic compound.
Compounds like (a) CH₄ (methane), (b) C₂H₆O (ethanol), and (d) C₆H₁₂O₆ (glucose) all feature carbon atoms covalently bonded to hydrogen and other elements, which is typical of organic compounds.