The correct option is A glucose
Carbohydrates are the polymers that are made up of monomers called a monosaccharide. The common monomers of carbohydrates are simple sugars like glucose and fructose. It is also one of the four basic macromolecules of life, Monosaccharides - these are the simple sugars. Mono means one and saccharides mean sugar. The monosaccharide consists of usually 3 to 7 carbons. If sugar has an aldehyde group(R-CHO) then it is known as aldose. If sugar has a ketone group(RC(=O)R') then it is known as ketose. The classification of monosaccharides is also dependent on the number of carbons in their sugar. When sugar consists of three carbons then it is known as trioses. Similarly five carbons (pentoses),six carbons(hexoses). Glucose is the most common monosaccharides and it is a very useful source of the energy. Energy is released from glucose and that energy is used to make adenosine triphosphate during cellular respiration. Plants also make glucose using carbon dioxide and water. This glucose is utilized by the plants for energy whereas maltose or malt sugar and generally found in the germinating grains. It is also the intermediate between the hydrolysis of glycogen and starch. It consists mainly of two molecules of glucose in an a-(1,4) glycosidic linkage. Amino acids form the building block of a protein. 75% of the body comprises amino acids. The amino acids involved in all body functions include growth and development, repair of damaged tissue, helps in normal digestion, and also provide energy to the body. Phospholipids regulate certain cellular processes and also consist of stabilizing and dynamic properties that can add an advantage in drug delivery.
So, the correct option is A.