The correct statement about the synthesis of pentaerythritol $(C(CH_2OH)_4)$ used in the preparation of $PETN$ is

• A
  The synthesis requires three aldol condensations and one Cannizzaro reaction
• B
  Alpha hydrogens of ethanol and methanol are involved in this reaction.
• C
  The synthesis requires two aldol condensations and two Cannizzaro reactions
• D
  The synthesis requires four aldol condensations between methanol and ethanol