The correct option is B 1nf=1(nf)oxidation+1(nf)reduction
The formula for calculation of n-factor(nf) for disproportionation reaction:
nf=(nf)oxidation×(nf)reduction(nf)oxidation+(nf)reduction
Taking reciprocal both sides
1nf=(nf)oxidation+(nf)reduction(nf)oxidation×(nf)reduction
1nf=(nf)oxidation(nf)oxidation×(nf)reduction+(nf)reduction(nf)oxidation×(nf)reduction
Hence,
1nf=1(nf)oxidation+1(nf)reduction