Which event occurred at a redshift around 1100?

Which event occurred at a redshift around 1100?
 
  a. big bang b. inflation
  c. CMB d. first stars formed

Question 2

Which of the following types of Universe has no center and no edge?
 
  a. closed b. flat
  c. open d. All of the other choices are correct.

Question 3

Which of the following agrees with a no-center, no-edge Universe?
 
  a. a flat geometry b. a positive-curved geometry
  c. a negative-curved geometry d. All of the other choices are correct.

Question 4

How old is the Universe since the big bang? Pick the best answer according to radioactive dating in the solar system, light travel times to most distant galaxies, time reversal of the big bang, and observations of the 3-K radiation.
 
  a. 1400 years
  b. 14,000 years
  c. 14,000,000 years
  d. 14,000,000,000 years