Which of the following are considered water supplies for sprinkler systems?

In determining suitable water supplies for sprinkler systems, it's essential to consider sources that can provide a reliable and adequate supply of water for fire protection. Municipal water is a common source as it is generally pressurized and readily available for firefighting purposes. Gravity tanks work by using gravity to provide a steady flow of water, which can be beneficial for maintaining pressure in sprinkler systems, especially during a fire.

Pressure tanks, which help maintain a specific level of pressure within the system to ensure that water can be efficiently distributed when needed, also qualify as a legitimate water supply. Together, municipal water, gravity tanks, and pressure tanks represent a comprehensive range of sources that can effectively support the functioning of sprinkler systems.

The other options, while mentioning some valid sources, do not encompass the full range of appropriate supplies. For instance, using only municipal water fails to acknowledge alternative sources that can enhance the system’s reliability. Options that focus exclusively on either a gravity tank or a reservoir tank with a pump miss the inclusion of other crucial elements like pressure tanks that bolster system performance. Hence, the correct answer reflects a complete understanding of the various water supply systems that can effectively serve sprinkler installations.