The hydrocarbon 2-methyl butane is an isomer of : (a) n-pentane (b) n-butane (c) propane (d) iso-butane
ASSERTION: n-Pentane and n-Hexane belong to a homologous series.
REASON: n-Pentane and n-Hexane belong to the same class of hydrocarbons and they differ by a - CH2 - group.