A rainbow can be seen in the sky
when the sun is behind you
Explanation of the correct answer
It is the correct option, if the sun is behind us then its reflection will be in front of us and we will be able to see the rainbow.
Explanation of the incorrect answer
It is an incorrect option, if the sun is in front of us then the rainbow forms behind us and we are unable to see it.
It is an incorrect option, because when the sun is above our head the rainbow may form in front of us or behind us.
It is an incorrect option because it is not necessary to be only at the time of sunrise, it can also be seen at different phases of the day.
Hence, the correct option is .