All organic substances possess 

Organic chemistry is the branch of chemistry that deals with compounds of carbon with other elements. Carbon being a tetravalent element bonds with the required number of hydrogen to find stability. Other atoms such as oxygen, nitrogen, sulfur, etc. are present in organic molecules as hetero atoms. The basic elements present in all organic compounds are carbon and hydrogen.

One of the many ways that organic compounds can be categorized is into natural and artificial substances. Natural chemicals include those made by plants or animals, such as sugar, a few terpenoids and alkaloids, certain vitamins like vitamin B₁₂, etc. 

Many are collected from plants and animals where they are available in reasonable amounts as they would be expensive to manufacture artificially. 

Molecules that are already naturally occurring in plants and animals are converted into new ones by interacting with synthetic compounds. The majority of synthetically generated organic molecules are obtained from petrochemicals, which are formed underground under high pressure and temperature and primarily consist of hydrocarbons. Many substances, like ethanol and insulin, are synthesized in factories using bacteria and yeasts rather than occurring spontaneously in nature.

Through a series of procedures known as the "carbon cycle," which starts with the transformation of carbon dioxide and a hydrogen source, such as water, into simple sugars and other organic molecules by energy sources like light, living things incorporate inorganic carbon compounds into organic compounds.

All organic molecules contain carbon and hydrogen, despite the fact that carbon can connect with several atoms.

Hence, the correct answer is option A.