Rays coming from the sun are refracted by the atmosphere. Due to this, the apparent sunset is about the actual sunset.

Correct option is C

Correct Answer: C 2 minutes before

Explanation:

The phenomenon responsible for this is atmospheric refraction. When light rays from the Sun pass through Earth's atmosphere, they bend towards the normal as they enter denser layers of air closer to Earth's surface. This causes the apparent position of the Sun to be higher than its actual position.

• During sunset, when the Sun is actually below the horizon, atmospheric refraction makes it appear above the horizon.
• This effect causes the apparent sunset to occur about 2 minutes later than the actual sunset (conversely, the apparent sunrise occurs about 2 minutes before the actual sunrise).
• Thus, we continue to see the Sun for about 2 minutes after it has actually set.

This delay is approximately 2 minutes, depending on atmospheric conditions like temperature, pressure, and humidity.

Information Booster:

• Atmospheric refraction occurs due to the variation in air density at different altitudes.
  
• This effect also causes the twinkling of stars, since light bends continuously as it passes through the atmosphere.
  
• The Sun appears flattened at the horizon due to differential refraction of light rays.
  
• Planets do not twinkle because they appear as small disks, and atmospheric refraction effects average out over the disk.
  
• The actual duration of the delayed sunset varies slightly based on location and atmospheric conditions.