For the circuit shown in the figure, the switch \( S \) is initially open, and the capacitor voltage is 70 V. The switch is then closed at time \( \mathrm{t}=0 \mathrm{~s} \) . Calculate the time required by the circuit for having a current of \( 5 \mu \mathrm{~A} \) .

A 37.6 s

B 68.5 s

C 48.5 s