2 - Methylbutane on reacting with bromine in the presence of sunlight gives mainly (a) 1 - bromo -2 - methylbutane (b) 2 - bromo -2 - methylbutane (c) 2 - bromo - 3 - methylbutane (d) 1 - bromo -3 - methylbutane
(b) : The reactivity order of abstraction of H atoms towards bromination of alkane is 3°H > 2°H > 1°H.