Substances in cells can be divided into two major categories: one has relatively small molecules, generally does not contain carbon, and cannot burn, such as water, inorganic salts, oxygen, etc. These substances are inorganic substances;

One type has relatively large molecules, generally contains carbon, and can burn sugars, lipids, proteins and nucleic acids. These substances are organic matter. For example, in wheat seeds, the substance that turns blue when exposed to iodine is starch, which is a characteristic of starch; what can be made into gluten is protein; the ashes left after the seeds are burned are inorganic salts, etc.

So choose: C