A siamese appliance combines two inlets into what number of outlets?

A Siamese appliance is designed specifically to allow for the simultaneous connection of two separate hose lines to a single outlet. The function of this appliance is to enable multiple incoming water supplies, such as from two fire hoses or other water sources, to come together and flow efficiently through a single outlet.

This configuration is highly beneficial in firefighting situations where increased water supply is needed. The ability to connect two inlets into one outlet allows fire crews to maximize their water delivery capabilities while maintaining a streamlined approach to attacking a fire.

None of the other choices correctly represent the design and purpose of a Siamese appliance, as they suggest multiple outlets, which is not feasible with this type of device. The single outlet ensures that all water being sent through the Siamese appliance is consolidated, providing a stronger and more focused water flow to tackle firefighting efforts.