Correct Answer - A
Alkyl groups have `+1` effect. By realeasing the electron density towards the `C` atom carrying the odd `e^(-)`, they decrease its electron deficiency and stabilize the free radical. Thus, the more the number of alkyl groups attached to the `C` atom which odd `e^(-)`, the greater would be the decrease of electron defficiency and hence more stable would be the radical:
`(CH_(3))_(3)C^(*) gt (CH_(3))_(2)CH_(2)^(*)gt CH_(3)`
