(freezing point depression) is a colligative property and depends upon the van't Hoff

factor (i), i.e. number of ions given by the electrolyte in aqueous solution.

where, molal freezing point depression constant
molality of the solution
and are constant

van't Hoff factor for ionic solution.
,
(Total ions thus, )
no ions
because glucose does not give ions.
aq
[Total ions , thus ]

[Total ions , thus, ]
Hence, will exhibit largest freezing point depression due to the highest value of .