A tertiary alkyl bromide reacts in aqueous ethanol at 50 ${}^{\circ }$C by a first-order process with half-life 3.0 h. Product analysis shows that 24% of the substrate consumed goes to alkene (E1) and the remaining 76% to substitution products (SN1). Take $\ln 2=0.693$. The first-order rate constant of the elimination pathway alone, in units of $10^{-5}{\mathrm{s}}^{-1}$, is closest to

1. A1.54
2. B4.88
3. C2.22
4. D6.42