Answer
(a) $ A=B=C $
(b) $ A\lt C \lt B $
Work Step by Step
(a) We know that $ A=B=C $ because in each of the three circuits, there is the same potential difference and hence they each have the same charge.
(b) We know that $ A\lt C \lt B $. The time required is proportional to the time constant, $RC$; hence, the ranking follows the equivalent resistance in the branch of the circuit where the current will come to a stop.
