[单选题]
The heat of fusion oj+rsu(3dh;l cf5l sjkra)(om5 ice is 80 kcal/kg. When 50 g of ice at $0 \; ^{\circ}C$ is added to 50 g of water at $25 \; ^{\circ}C$, what is the final temperature?
A. $0 \; ^{\circ}C$
B. $12.5 \; ^{\circ}C$
C. $17.5 \; ^{\circ}C$
D. $20 \; ^{\circ}C$
