Multiple choice

A red giant occurs when:

  1. Nucleosynthesis has stopped

  2. Hydrogen has been depleted at the star's core

  3. Elements heavier than carbon have been synthesized

  4. A star gets really angry

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A star becomes a red giant when it exhausts the hydrogen fuel in its core. This causes the core to contract and the outer layers to expand and cool.