What is the freezing point of a solution made by dissolving 0.848 g of biphenyl (C₁₂H₁₀) in 25.0 g of cyclohexane, given that cyclohexane has a freezing point of 6.50 °C and a kf of 20.0 °C/m?

a) 6.50 °C
b) 4.56 °C
c) 8.62 °C
d) 10.80 °C