The hyperconjugative stabilities of tert-butyl cation and 2-butene, respectively, are due to
(A) σ→p (empty) and σ→π∗ electron delocalisations
(B) σ→σ∗ and σ→π electron delocalisations
(C) σ→p (filled) and σ→π electron delocalisations
(D) p (filled) →σ→π∗ electron delocalisations
