Which of the following organic compounds is the main source of energy for living things?

a. carbohydrate
b. lipids
c. nucleic acids
d. proteins

The main source of energy in organic compounds  for living things is Carbohydrate.

Carbohydrates are the nutrients composed of starches, sugars,and dietary fiber found in  plant and animal products..

They are called the main  energy source for living things because once ingested, they have a very direct and fast metabolic rate,considering the fact that carbohydrate digestion begins in the mouth by the enzyme amylase released by saliva. This energy immediately reaches the whole body especially the brain and makes the body agile.

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its carbohydrates

Explanation:

segmentation=endoskeleton=backbone=coelom=tissues

a chair, a bed, and a toothbrush

explanation: