Light travels through a vacuum and then passes into a glass block. In the glass block, the speed of the light is $2.0 \times 10^8\,\text{m s}^{-1}$. Which statement about the speed of light is correct?
- AThe speed in a vacuum is 1.5 times the speed in the glass.
- BThe speed in the glass is the same as the speed in a vacuum.
- CThe speed in the glass is 1.5 times the speed in a vacuum.
- DThe speed in the glass is $1.0 \times 10^8$ times the speed in a vacuum.