Which among the following free radicals is most stable? (a) (b) (c) (d) GENERAL ORGANIC CHEMISTRY

Free radicals are stable due to contribution of three factors- (1) Resonance (2) Hyper-conjugation (3) Inductive effect In option (a), resonance is taking place effectively which is shown in the figure. Also, there are 3 carbon which is contributing to the stability of free radical. Hence, it is the most stable free radical. In option (b), there is no conjugation due to 3 sp hybridisation of carbon making it the most unstable free radical. In option (d), allyl free radical is there which also is in resonance (shown in the figure) but lacks effective hyper-conjugation if compared with option