Fe(OH)2 is not soluble in water, this is a heavy metal hydroxide and they are known for not being soluble in water.
LiNO3 is soluble in water, nitrates (which are salts) are, in most of the cases, soluble in water.
NH4Cl is soluble in water, chlorides are, in most of the cases, soluble in water.
Li2S is soluble in water, sulphides are not usually soluble in water, except for the alkaline and alkaline earth sulphides, which are very soluble in water (Litium is an alkaline metal).
It means that 3 of the given compounds are soluble in water.
The correct choice is 3.