A: 6%
\begin{aligned}\text { Reading from appointment: } \%&=86 \% \text { (cumulative) } \\\text { Reading from train or bus delay } \%&=92 \% \text { (cumulatice) } \\\therefore \text { train or bus delay }&=92 \%-86 \% \\&=6 \%\quad \therefore A\end{aligned}
