Final answer:
Primary (physical) treatment option (D) is the phase in wastewater treatment that removes floating fats, oils, greases, and settleable inorganic and organic material.
Step-by-step explanation:
The type of treatment that removes floating fats, oils, greases, and settleable inorganic and organic material is Primary (physical) treatment option (D). In the primary treatment phase of wastewater treatment, sewage is stored in a basin where these materials can either rise to the top or settle to the bottom and are then removed. The resulting sludge is treated separately, while the clarified water moves on to secondary treatment.
By removing these larger and easily separable components, primary treatment sets the stage for subsequent treatment processes. It helps reduce the load on downstream treatment units, making the overall treatment more effective.