Answer: Option (3) is the correct answer.
Step-by-step explanation:
It is known that like dissolves like that is, a polar solvent will dissolve only polar compounds. Whereas a non-polar solvent will dissolve only non-polar compound.
Substances whose atoms have large difference in electronegativities are polar in nature. Water is a polar solvent and it is able to dissolve polar molecules.
For example, HCl is a polar or ionic compound so it is soluble in water.
On the other hand,
,
, and
are all non-polar as bond between them is formed due to sharing of electrons.
Hence, we can conclude that at STP, HCl is the substance that is most soluble in
.