Arrange the following in order of increasing order of their stability.

+M effect of NH2 group disperse the charge of carbocation, hence increases the stability and –CH3 group shows +I effect, so it will disperse the charge less than –NH2 group .:CH is triplet carbene, which has least tendency to release electron, hence makes the carbocationless stable. Whereas –NO2 group shows –M effect due to which the positive charge on the carbocation increases, hence stability decreases.Hence, the correct answer is (2).