The correct option is A 100∘C
Heat required to melt 1g of ice at 0∘C to water at 0∘C=1×80 cal.
Heat required to raise temperature of 1 g of water from 0∘ C to 100∘ C=1×1×100=100cal
Total heat required for maximum temperature of 100∘C = 80 + 100 = 180 cal
As one gram of steam gives 540 cal of heat when it is converted to water at 100∘C,
therefore, temperature of the mixture would be 100∘C.