Potassium tert-butoxide gives a higher proportion of the Hofmann alkene than sodium ethoxide with the same alkyl halide mainly because:

1. Ait is a weaker base than ethoxide, so the reaction becomes E1
2. Bits bulk makes approach to the hindered internal beta-hydrogen difficult, so the more accessible terminal hydrogen is removed
3. Cit changes the leaving group of the substrate
4. Dthe less substituted alkene is always the more stable one