Consider the change in oxidation state of Bromine corresponding to different emf values as shown in the diagram below : <br> $BrO_4^- \xrightarrow{1.82 V} BrO_3^- \xrightarrow{1.5 V} HBrO \xrightarrow{1.595 V} Br_2 \xrightarrow{1.0652 V} Br^-$ <br> Then the species undergoing disproportionation is

Question

( A ) $BrO_4^-$
( B ) $Br_2$
( C ) $HBrO$
( D ) $BrO_3^-$