Consider the following four halogen containing organic compounds:

 

 

 

 

 

 

 

Choose the correct statement(s) among the following regarding the reactions of these compounds.

II is more reactive than I towards methanol.

IV is more reactive than III towards PhSNa.

On heating with  $\text{EtONa}/\text{EtOH,}$ II gives single alkene while IV gives three isomeric alkenes.

On nucleophilic substitution by  $\text{NaSH}$, IV gives an optically pure primary thiol as the major product.