The sun is visible a little before the actual sunrise because
of which one of the following?

Sun is visible a little before the actual sunrise and until a little after a actual sunset. This is due to

Sun is visible a little before the actual sunrise and until a little after a actual sunset. This is due to

The sun is seen on the horizon a little before sunrise.

We can see the sun before the actual sunrise by about :

Explain why is the sun visible a little before actual sunrise and a little after actual sunset.