The correct answer for the question that is being presented above is this one: "Either Within the first five minutes or Sometime after the first five minutes."
1. galaxies formed => Sometime after the first five minutes.
2. antielectrons (positrons) as common as electrons => Within the first five minutes
3. photons of cosmic microwave background released => Sometime after the first five minutes
4. temperature fell to 10^15 K => Within the first five minutes
5. strong force and electroweak force first became distinct => Within the first five minutes
6. carbon nuclei formed by fusion => Sometime after the first five minutes
7. inflation occurred => Within the first five minutes
8. stars formed => Sometime after the first five minutes