A ray of light travels from a vacuum into glass as shown below.

In glass, light has speed v. In a vacuum, light has speed c. Which of the following gives the refractive index of glass?

A. \(\frac{c}{v}\)

B. \(\frac{v}{c}\)

C. \(\frac{{\sin c}}{{\sin v}}\)

D. \(\frac{{\sin v}}{{\sin c}}\)

A