One of the following statements is Not True about SN2 reactivity of the alkyl halides?
a.
Alkyl halide with branching next to the leaving group contributes greatly to the slowness of reaction of secondary halides.
b.
Tertiary alkyl halide reacts much more slowly than the secondary alkyl halide.
c.
Methyl halides are the most reactive substrates.
d.
Vinylic and aryl halides are the most reactive types of halides due to the presence of double bond and resonance in their respective molecules.