Question

what caused our sun to ignite and become a star?
○ fusion reactions within the sun
○ chemical reactions with the sun
○ gravity
○ heat

Explanation:

To determine what caused the Sun to ignite, we analyze each option:

• Fusion reactions are the result of ignition, not the cause of it starting.
• Chemical reactions don't provide enough energy for stellar ignition.
• Gravity pulls matter in the protostar (pre - Sun) together, increasing pressure and temperature until nuclear fusion (ignition) starts.
• Heat is a result of the process, not the initial cause of ignition.

Answer:

C. Gravity