Fact 1: Plants release oxygen during the day but not during the night.

Fact 2: When it is day the sun is out.

Given the two facts above, answer the question "When do plants release oxygen?" with the following options: 
- When the sun is out
 - heat produced
 - in the autumn season
 - flow of electrons
 - When there is a full moon
 - During nighttime hours
 - When the stars are out
 - metabolic reaction


 

 When the sun is out        