Two rays, each with an angle of incidence of $60^{\circ}$, enter dilute and concentrated sugar-water solutions. The refracted paths are shown. Which row is correct?
- Arefractive index decreases as concentration increases; speed through solution decreases as concentration increases
- Brefractive index decreases as concentration increases; speed through solution increases as concentration increases
- Crefractive index increases as concentration increases; speed through solution decreases as concentration increases
- Drefractive index increases as concentration increases; speed through solution increases as concentration increases