A man in an empty swimming pool has a telescope focused at 4'O clock sun. When the swimming pool is filled with water, the man (now inside the water with his telescope undisturbed) observes the setting sun. Find the refractive index of water, if sun rises and sets at 6'O clock.

• A. \[\frac{4}{3}\]
• B. \[\frac{2}{\sqrt{3}}\]
• C. \[\frac{8}{5}\]
• D. \[\frac{2}{5}\]