A block of mass‘m’is connected to two springs of stiffness $$K_1$$ and $$K_2$$ as shown in the figure $$f_1$$ and $$f_2$$ are the frequencies of the block when connected to $$K_1$$ and $$K_2$$ independently. Then the frequency of ‘m’ when connected to $$K_1$$ and $$K_2$$ as in the figure is

A

$$f = f_1 + f_2$$

B

$$f = f_1^2 + f_2^2$$

C

$$f = \sqrt{f_1^2 + f_2^2}$$

D

$$f = \sqrt{f_1^2 - f_2^2}$$