Boil the water and cool it before you keep it in the fridge.

A. Let the water be boiled and cooled before it is kept in the fridge.
B. Let the water be boiled and cooled before it is kept in the fridge by you.
C. Let the water be boiled by you and cooled by you before it is kept in the fridge.
D. Let the water be boiled, cooled and kept in the fridge.