You are presented with the question "When do plants release oxygen?" and the following answer choices: 
- 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

Now knowing that plants release oxygen during the day but not during the night and when it is day the sun is out, choose the best answer.


 

 When the sun is out        