A star more massive than the Sun will have A) an identical ...

[mmm]

A star more massive than the Sun will have
 
  A) an identical lifetime as the Sun because although its overall mass is higher, the mass of its nuclear burning core is the same
  B) a longer lifetime because it has more fuel to burn
  C) a shorter lifetime because although its overall mass is higher, the mass of its nuclear burning core is smaller
  D) a shorter lifetime because its central core is hotter and denser

Question 2

Why do the oldest stars we observe contain almost nothing but hydrogen and helium?
 
  What will be an ideal response?

[tofugiraffe]

Answer to Question 1

D

Answer to Question 2

This first generation of stars must be made of the elements produced in primordial nucleosynthesis, which had time only to turn 25 of the hydrogen into helium.