Let the volume of mixture A be 200‌ml, which implies the quantity of cocoa in the mixture is 120‌ml, and the quantity of sugar ln the mixture 80‌ml. Similarly, let the volume of the mixture be 300‌ml, which implies the quantity of coffee, and sugar in the mixture is 210 , and 90‌ml, respectively. Now we combine mixture A, and B in the ratio of 2:3 (if 200‌ml mixture A, then 300‌ml of mixture B ). Hence, the volume of the mixture C is (200+300)=500‌ml, and the quantity of the sugar is (90+80)=170‌ml. Now he mixes C with an equal amount of milk to make a drink, which implies the quantity of the final mixture is (500+500)=1000‌ml The quantity of sugar in the final mixture is 170‌ml. Hence, the percentage is 17% The correct option is A