A beam of light moves through a vacuum and then passes into a transparent liquid. The diagram shows its route. In the vacuum, the light travels at a speed of $3.0 \times 10^8\text{ m/s}$. What is the speed of light in the liquid?
- A$1.9 \times 10^8\text{ m/s}$
- B$2.0 \times 10^8\text{ m/s}$
- C$4.6 \times 10^8\text{ m/s}$
- D$4.8 \times 10^8\text{ m/s}$