Which one of the following structural formulae of two organic compounds is correctly identified along with its related function?

• A
  $B$ : Adenine - $A$ nucleotide that makes up nucleic acids
• B
  $A$ : Triglyceride - Major source of energy
• C
  $B$ : Uracil - $A$ component of $DNA$
• D
  $A$ : Lecithin - $A$ component of cell membrane