Wurtz reaction is a coupling reaction, which is used to prepare symmetrical alkanes. It is

basically a reaction in which higher alkanes are synthesised by a reaction in between alkyle halides and metallic sodium. This reaction takes place in presence of dry ether. As we know that less stable radical is more reactive towards wurtz reaction. Therefore, the order of reactivity towards wurtz reaction is - carbocation (least stable) -carbocation (less stable) -carbocation (most stable) in option 2 and 3 most stable and carbocations are formed which are stablized by phenyl ring. In option

stable carbocation is formed. Hence, will be most reactive.