Missing question:
a) benzene, Kf = 5.12°C/m.
b) ethanol, Kf = 1.99°C/m.
c) chloroform, Kf = 4.70°C/m.
d) carbon tetrachloride, Kf = 29.9°C/m
e) diethyl ether, Kf = 1.79°C/m.
Answer is: d) carbon tetrachloride, Kf = 29.9°C/m.
b(solution) = 0,2 m.
ΔT = Kf · b(solution).
Because molality (b) is constant, greatest freezing point lowering is solution with highest Kf (the freezing point depression constant).