They first sun-dried the garbage for one to three days to bring down the moisture level.

• A. The garbage was first sun-dried for one to three days to bring down the moisture level.
• B. The moisture level of the garbage came down when it was sun-dried for one to three days.
• C. One to three days of sun-drying brought down the moisture level of the garbage.
• D. The moisture level was brought down by sun-drying the garbage for one to three days.