If chlorine dissipates rapidly if outside during the day, then what make chlorine dissipate rapidly?

Answer choices:
- being kept in the dark
 - local weather changes
 - fissures of hot, acidic water
 - being outside at night
 - being outside during the day
 - circulatory systems
 - being contained in a bottle
 - The bending of a ray of light

 

     being outside during the day     