Four major classes of organic compounds found in living organisms are proteins, carbohydrates,
a: vitamins, and minerals
b: lipids, and nucleic acids
c: sugars, and fats
d: saccharides, and fatty acids

The correct answer for the fill in the blank is B) lipids, and nucleic acid.

There are four major organic compound, which are present in all living organisms. They are proteins, carbohydrates, lipids, and nucleic acids.

Proteins help in performing all essential functions in the body. Their building blocks are amino acids,which are linked by peptide bond.

Carbohydrates are the major source of energy in the living systems. They are made up of simple sugars like monosccharides and disaccharides.

Lipids consist of compounds like fats and oils. They form the striuctural components of the cell.

Nucleic acid include DNA ( deoxyribonucleic acid) and RNA ( ribonucleic acid). They store genetic information, which is passed from one generation to the next generation.

Thus, all these four organic compounds are essential for the survival of living organisms.

if you add everything up correctly you should get 69 i got this because 50 plus 19 is it