Screening is the method adopted for removing ______ from water. 

Explanation:

Water treatment is the process of removing all those substances, whether biological, chemical, or physical, that are potentially harmful to the water supply for human and domestic use. This treatment helps to produce water that is safe, palatable, clear, colorless, and odorless. Water also needs to be non-corrosive. The method of treatment employed depends on the nature of raw water constituents and the desired standard of water quality.

The unit operations in water treatment includes;

Screening:

To protect the main units of a treatment plant and aid in their efficient operation, it is necessary to use screens to remove any large floating and suspended solids present in the inflow. These materials include bushes, wood, leaves, twigs, paper, rags, and other debris that could obstruct flow through the plant or damage equipment.

Hence option (2) is correct.