For a compressible flow, Mach Number (M) is given by which of the following expression? where v = velocity of fluid in compressible flow c = speed of sound in air

A

$$M = \frac{V}{\sqrt{c}}$$

B

$$M = \frac{c}{v}$$

C

$$M = \frac{v}{c}$$

D

$$M = \frac{v}{c^{2}}$$