# In which of the following pair one species is incorrectly indicated which would give higher substitution \elimination ratio when it reacts with isopropyl bromide.

\begin{array}{1 1}(a)\;eto^-\;or \;tbuo^-\\(b)\;cl^-\;or\;br^-\\(c)\;OCN^-\;OR\;SCN^-\\(d)\;CH_3S^-\;OR\;CH_3O^-\end{array}

Greater the basicity higher the elimination\substitution and greater the nucleophilicity higher substitution \elimination except in $OCN^-\;OR\;SCN^-$ all are correctly matched.