[单选题]
The heat of fusion of ice is 80 kcapa4jrx5m hgt8u;hd y)9a* 8lp l/rizgp+/ 9*a,.xy-ldxf 8ruo hkg. 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. $20 \; ^{\circ}C$
