The answer is B, carbohydrates.
Carbohydrates are the first choice of the energy source of your body, they can be broken down into simple and soluble compounds such as glucose. These can be used by cells for respiration to generate energy for activities such as growth, movement, repair etc. Besides using for respiration, they are also capable of forming cell structures such as cellulose.
At least 75% of the history of the earth
Another name for unicellular organisms that dominated Earth up to the Precambrian time is prokaryotes. The correct answer is D.
In my opinion the best sounding answer is C I hope this helpes<span />
