Which of the following is common in nature?

Answer: Option C

D sugars and L amino acids are common in nature.
D- and L- is a way of describing the absolute configuration of molecules that pre-date the (R, S) CIP system. D- and L-is an old but still-convenient shorthand for saying that molecules are enantiomers.
These compounds are called R and S enantiomers (or isomers). However, when amino acids or sugars are chiral, scientists call them D and L isomers. D- means “right-handed” and L- means “left-handed.”