Nucleotides Have Which One of the Following Functions, in Addition

Nucleotides have which one of the following functions, in addition to being components of the nucleic acids DNA and RNA?

A) They transport cholesterol in the bloodstream
B) They act as a hormone, triggering the breakdown of glycogen to release glucose
C) They form a component of the cell membrane, and help to maintain its fluidity
D) They act as a store of energy to help power biochemical reactions