What is the time difference between the actual sunset and apparent sun

What is the time difference between the actual sunset and apparent sunset ?

About half a minute
About one minute
About two minutes
About twenty minutes
This question was previously asked in
UPSC CISF-AC-EXE – 2022
The time difference between actual sunset and apparent sunset is caused by atmospheric refraction. Sunlight bends as it passes through the Earth’s atmosphere because the density of the atmosphere increases towards the Earth’s surface.
This refraction causes the sun’s rays to bend downwards, making the sun appear higher in the sky than its actual position. Near the horizon, this effect is most pronounced. As a result, the sun appears to rise earlier in the morning (apparent sunrise before actual sunrise) and set later in the evening (apparent sunset after actual sunset).
The apparent flattening of the sun’s disc near the horizon is also a result of atmospheric refraction. The time difference between actual and apparent sunrise or sunset is typically about 2 minutes. This phenomenon effectively increases the duration of daylight by about 4 minutes each day (2 minutes in the morning and 2 minutes in the evening).