What type of valve has two ports and allows fluid flow in both directions?

The choice is based on the definition and functioning of a 2/2 way valve. This type of valve is specifically designed with two ports, which means it has one inlet and one outlet. Its design allows for fluid to flow in both directions, making it suitable for situations where the direction of flow can change, such as in certain plumbing or hydraulic applications.

In contrast, the other options represent valves with different configurations and functions. A 3/2 way valve has three ports and allows flow between three connection points, thus managing flow in a more complex manner than a simple two-port setup. A 4/2 way valve offers four ports and is typically used to control the direction of flow in a more intricate system. Likewise, a 4/3 way valve has four ports but allows for three different flow paths, making it suitable for controlling actuators or other components.

The 2/2 way valve's straightforward design allows for bidirectional flow, which is essential in many basic fluid control applications.