Question $35)$ The test voltage and minimum insulation resistance test values for an installation forming part of a $230$ V single phase, TN$-$C$-$S system are... a$)500$ V and $0\mathrm{.}5$ MQ b$)250$ V and $1\mathrm{.}0$ MQ c$)250$ V and $0\mathrm{.}5$ MO d$)500$ V and $1\mathrm{.}0$ MQ