Which of the following exist as dimer?

Given data: It is given to find which of the following exist as dimer

Concept Used:  Sulphur and its compounds.

Detailed Solution: Sulfur's octet is incomplete without two electrons, but because its d-orbitals are vacant, it can increase its octet.

S is bound to Cl in sulphur monochloride ($\mathrm{S}-\mathrm{Cl}$), preventing it from completing its octet.

So, the S atom from one $\mathrm{S}-\mathrm{Cl}$ joins the S atom from another $\mathrm{S}-\mathrm{Cl}$ to form a new connection.

As a result, S-Cl typically occurs as dimer. The S atom completes its octet in this manner.