What is the best way to change the sentence below from active voice to passive voice?

People water their gardens more than once a week during the summer.
A.
Gardens are watered more than once a week during the summer.
B.
During the summer, the rainfall may water the gardens more than once a week.
C.
Come summer, you water gardens more than once a week.
D.
Somebody will water gardens more than once a week during the summer.