Which type of heating system is known for distributing heated air through ducts?

The correct choice identifies forced air heating systems, which are specifically designed to distribute heated air throughout a building using ductwork. This system works by heating air via a furnace or heat exchanger and then using blowers to push the heated air through a series of ducts, ensuring that every room receives adequate warmth.

In contrast, hydronic heating systems utilize water as the medium for heat transfer, circulating hot water through pipes to radiators or underfloor heating systems, without relying on air ducts. Geothermal heating systems draw heat from the ground or groundwater and typically use water to distribute the heat, rather than air. Electric baseboard heating systems operate independently by using electric resistance to generate heat directly in the baseboards of rooms, also bypassing the need for ductwork.

Thus, forced air heating systems are distinctive in their use of ducts to deliver warm air, making them the correct answer to the question about heating systems that distribute heated air.