The reaction, S+H2SO4(conc)→X+Y;  is an example of

Increase in oxidation no. of  'S'  in elemental sulphur= 4Decrease in oxidation no. of 'S' in sulphuric acid = 2Sulphur oxidizes to SO2H2SO4 reduces to SO2Both oxidant and reductant give same product.This is a Comproportionation reaction