In the circuit shown below the switch is closed at $$t = 0$$. For $$0 < t < R(C_1 + C_2)$$, the current $$I_1$$ in the capacitor $$C_1$$ in terms of total current $$I$$ is

A

$$\left(\frac{C_1}{C_2}\right)I$$

B

$$\left(\frac{C_2}{C_1}\right)I$$

C

$$\left(\frac{C_1}{C_1 + C_2}\right)I$$

D

$$\left(\frac{C_2}{C_1 + C_2}\right)I$$