- A candle is a source of light when it is burned
- A source of something emits / produces / generates / provides that something
- Hence, a candle produces light when it is burned

- A candle produces light when it is burned
- A star produces light and heat
- So, both candles and stars produce light

So, both candles and stars produce light
Q: Which two objects produce their own light?
Context:
- A star produces light and heat 
- A candle is a source of light when it is burned 
- A source of something emits / produces / generates / provides that something