Which of the following does not return carbon to the atmosphere?
A) formation of carbonate rocks

B) decay of once-living things

C) as waste from cellular respiration

D) burning of fossil fuels

B) the decay of once-living things
Hope this helps have a great day!

Six amino acids have side chains that are polar but not charged. these are serine (ser), threonine (thr), cysteine (cys), asparagine (asn), glutamine (gln), and tyrosine (tyr). these amino acids are usually found at the surface of proteins, as discussed in the proteins 2 module.

Bis the correct answer.