The correct answer is: C. Hydrocarbon
Oils are a type of hydrocarbon, which is a compound that is made up of hydrogen and carbon atoms. Hydrocarbons are the most abundant type of organic compound on Earth, and they are found in a variety of forms, including oils, fats, waxes, and natural gas.
Carbohydrates are a type of organic compound that is made up of carbon, hydrogen, and oxygen atoms. Carbohydrates are the main source of energy for the human body, and they are found in a variety of foods, including bread, pasta, rice, and potatoes.
Proteins are a type of organic compound that is made up of carbon, hydrogen, oxygen, nitrogen, and sulfur atoms. Proteins are essential for the growth and repair of tissues in the human body, and they are found in a variety of foods, including meat, fish, eggs, and dairy products.
Esters are a type of organic compound that is made up of carbon, hydrogen, oxygen, and oxygen atoms. Esters are found in a variety of foods, including fruits, vegetables, and nuts. They are also used in a variety of products, including perfumes, cosmetics, and cleaning products.
In conclusion, the correct answer to the question “By which organic compound all the oils are known?” is C. Hydrocarbon.