The compound `(B)` (2,3- dimethyl butane) is formed mainly because of `H^(ddot(Θ))` (hydride ion) transfer from alkane
to more stable `3^(@) C^(o+)`.
But `(A)` is not formed mainly because `H^(ddot(Θ))` (hydride ion) transfer from alkane
to less stable `1^(@)C^(o+)` takes place.
