Which option identifies the best ipm method to reduce bacteria count in the following scenario?

meredith needs to treat a severely infected field before planting out a crop, to reduce common, soil-dwelling anaerobic bacteria that cause root rot, but can be destroyed by exposure to light and oxygen.

plant a trap crop near the field
till the field twice before planting
saturate the field with an antibacterial solution
rotate crops in the field the season before planting