The balanced chemical equation is;

CS2 + 3O2 → CO2 + 2SO2

Since molecular mass of CS2 is 12+ 64 =76g/mol

The given mass is 7.6g,

Hence number of moles of CS2 = 7.6/76 = 0.10 moles

The molecular mass of O2 is 32g/mol

The given mass of O2 is 12.8g

Hence number of moles of O2 = 12.8/32 =0.13

Since CS2 is taken in less amount, it is limiting reactant.

Hence, option A is correct.