A parallel plate capacitor having plates of area S and plate separation d, has capacitance $$C_1$$ in air. When two dielectrics of different relative permittivities $$(\epsilon_1 = 2$$ and $$\epsilon_2 = 4)$$ are introduced between the two plates as shown in thefigure, the capacitance becomes $$C_2$$. The ratio $$\frac{C_2}{C_1}$$ is

A

$$\frac{6}{5}$$

B

$$\frac{5}{3}$$

C

$$\frac{7}{5}$$

D

$$\frac{7}{3}$$