Water vapour comes out from the plant leaf through the stomatal opening. Through the same stomatal opening carbon dioxide diffuses into the plant during photosynthesis. Reason out the above statements using the following options. 

1. Both process can happen together because the diffusion coefficient of water and CO₂ is different. 

2. The above processes happen only during night time

3. One process occurs during the day time and the other night

4. Both processes cannot happen simultaneously