Aplanet rotating causes cycles of day and night on that planet, and the gravitational pull of the major planets alters the orbital period from revolution to revolution. Given these facts, what causes day and night among the following options:
- chemical messengers
 - The moon
 - The ocean's waves
 - chemical reaction
 - Revolution around the sun
 - The clock on the wall
 - Evaporation of water
 - Basic units of the plant body.


 

     Revolution around the sun    