Which of the following oxidation reactions are carried out by both $K_2Cr_2O_7$ and $KMnO_4$ in acidic medium?
$A. I^{-} \rightarrow I_2$
$B. S^{2-} \rightarrow S$
$C. Fe^{2+} \rightarrow Fe^{3+}$
$D. I^{-} \rightarrow IO_3^-$
$E. S_2O_3^{2-} \rightarrow SO_4^{2-}$
Choose the correct answer from the options given below:

• A
  $A, B$ and $C$ only
• B
  $A, D$ and $E$ only
• C
  $A, B$ and $D$ only
• D
  $C, D$ and $E$ only