SAYTZEFF'S RULE for elimination reactions states that

1. NCERT §6.5 (Elimination reactions): when there's a CHOICE of which $\beta$-H to remove (giving different alkene products), the more SUBSTITUTED alkene predominates. 2. Why? More substituted alkenes are MORE STABLE (alkyl groups donate electrons by hyperconjugation, stabilising the double bond). 3. Example: 2-bromobutane $\mathrm{(CH_3)CHBr(CH_2CH_3)}$ + alcoholic KOH → mostly but-2-ene ($\mathrm{CH_3CH{=}CHCH_3}$, more substituted) rather than but-1-ene ($\mathrm{CH_2{=}CHCH_2CH_3}$, less substituted). 4. Named after Russian chemist Alexander Saytzeff (Zaitsev) who proposed it in 1875. 5. Option B describes the COUNTER rule (Hofmann's, which applies with bulky bases like $t$-butoxide). Option C is irrelevant. Option D is wrong physical chemistry. _Source: NCERT Class 12 Chemistry Part 2, Ch 6, §6.5 (Elimination — Saytzeff's rule), p. 13._