In the listed life cycle, which stage comes immediately after Sun-like star?

• A. Red giant
• B. Nebula
• C. White dwarf
• D. Black dwarf

Answer: (A)

When a Sun-like star finishes its main-sequence phase, it runs out of hydrogen in the core. The core contracts and heats up, while the outer layers expand and cool, so the star becomes a red giant. This expansion is the next stage in its life after the Sun-like (main-sequence) phase. The nebula is the cloud from which stars form, so it comes earlier in the cycle. A white dwarf would come after the red giant, once the outer layers are shed and the hot core remains. A black dwarf would be an even later, extremely long-term cooling stage of a white dwarf.