When a pump is inactive, what is the state of conditions described as?

The correct choice is the state referred to as static when a pump is inactive. In this context, "static" describes a condition where there is no flow and the fluids are at rest, meaning that no energy is being added to the system through motion.

This situation signifies that the forces acting on the fluid are balanced, which is essential for understanding various engineering principles relating to fluid mechanics. For example, when assessing system pressures and potential energy, it's crucial to recognize whether the fluid is static or dynamic.

The other terms, while they may describe similar or related conditions in different contexts, do not specifically denote the condition of a pump being inactive. "Dynamic" refers to situations involving movement and flow, which is the opposite of what occurs when the pump is not operational. "Inactive" is a descriptive term but does not specifically indicate the state of the fluid. "Quiescent" can imply a state of rest, akin to static, but is less commonly used in engineering terminology to describe a fluid that is not in motion within the context of pump operation.