The smallest mains in a water distribution system are called distributors.

• A. Indicating feeders
• B. Secondary feeders
• C. Primary feeders
• D. Distributors

Answer: (D)

In a water distribution network, pipe segments are named by size and function as water moves from the main supply toward users. The largest trunk is the water main, and from it come feeders that carry water farther into the system. Among these, the smallest main lines are the ones that actually distribute water to local areas and service connections—these are called distributors. They feed the smaller service lines and hydrants in a neighborhood, acting as the last major distribution step before water reaches individual users. That’s why the term that fits “the smallest mains” is distributors.

The other terms refer to larger lines that serve broader areas, so they don’t match the description of the smallest mains.