Organic Chemistry

9.
a. Using Fischer projections, draw all the possible stereoisomers 2, 4-dihydroxybutane (CH3-CHOH-CHOH-CH3)
b. Label the relationships of your answers in "A" as enantiomers, diastereomers, or Meso ( if any)
c. Assign absolute configurations to the chiral carbons n one of your Fischer projections.
d. Indicate which of the compounds you have drawn would be optically active. Explain your reasoning.