A system of capacitors $$C_1 = 4\,\mu F$$, $$C_2 = 1\,\mu F$$, $$C_3 = 2\,\mu F$$ and $$C_4 = 3\,\mu F$$ connected across a battery of emf E = 15 V is shown in figure. The charge that will flow, through the switch K, when it is closed, is

A

$$15\,\mu C$$ c to d

B

$$12\,\mu C$$ c to d

C

$$6\,\mu C$$ d to c

D

$$9\,\mu C$$ d to c