The correct statement about the synthesis of erythritol $\left(\mathrm{C}{\left({\mathrm{CH}}_2\mathrm{OH}\right)}_4\right)$ used in the preparation of PETN is:

The synthesis requires three aldol condensations and one Cannizzaro reaction.

Alpha hydrogens of ethanol and methanol are involved in the reaction

The synthesis requires two aldol condensations and two Cannizzaro reactions.

The synthesis requires four aldol condensations between methanol and ethanol