The link reaction between glycolysis and the Krebs cycle is..............

• A
  Pyruvate $\rightarrow$ Acetyl $CoA$
• B
  $PGAL$ $\rightarrow$ $1,3-BIPGA$
• C
  Citric acid $\rightarrow$ Isocitric acid
• D
  Malic acid $\rightarrow$ $OAA$