Which of the following best demonstrates the sensitivity of human vision under optimal conditions?

• A. Humans can read fine print from 100 feet away.
• B. Humans can differentiate between shades of black and white under very low light.
• C. Humans can perceive the light of a flashlight pointed towards the sky from 50 miles away.
• D. Humans can see the light from a lighthouse 100 miles away on a clear night.

Answer: (B)