For 1 molal aqueous solution of the following compounds, which one will show the highest freezing point?

ΔTF=ixm×KFm=1(given)
ΔTF=i×Kf
for ionic compounds vant Hoff factors is equal to the number of discrete ions in a formula unit of the substance.
In First option 1 number of ions=4
In second option 2 Number of ions=3
In third option 3 Number if ions=4
In forth option 4 Number if ions=2
So, value if i will be lowest in option 2 [Co(H2O)3Cl3].3H2O
So, option 2 will have lowest freezing point depression (ΔTf), so it will have highest freezing point.