That quasars were at cosmological distances yet appeared like ordinary faint stars meant:

That quasars were at cosmological distances yet appeared like ordinary faint stars meant:
 
  A) they were the brightest stars ever observed.
  B) they must be very large.
  C) they must contain many O and B type stars.
  D) they must be producing such large quantities of energy than even fusion could not explain their output.
  E) they must be very small, but bright due to gravitational lensing.

Question 2

How many helium nuclei fuse together when making carbon?
 
  A) 2
  B) 3
  C) 4
  D) varies depending on the reaction
  E) none of the above

Question 3

According to our present theory of solar system formation, why were solid planetesimals able to grow larger in the outer solar system than in the inner solar system?
 
  A) because the Sun's gravity was stronger in the outer solar system, allowing more solid material to collect
  B) because only metal and rock could condense in the inner solar system, while ice also condensed in the outer solar system
  C) because gas in the outer solar system contained a larger proportion of rock, metal, and hydrogen compounds than the gas in the inner solar system
  D) because only the outer planets captured hydrogen and helium gas from the solar nebula

Question 4

Why do models suggest that Uranus and Neptune formed elsewhere?
 
  A) We do not have very good models.
  B) The density of materials was too low in their current orbits for the ice giants to have formed there.
  C) Jupiter and Saturn took up most of the material in the area; Uranus and Neptune must have formed elsewhere.
  D) It is too cold at their current locations for the ice giants to have formed there.