The time needed for an output to change from the result of an input change is known as:1 pointnoise immunityfan-outrise timepropagation delay

The time needed for an output to change from the result of an input change is known as propagation delay.

Explanation:

Propagation delay refers to the time it takes for a signal to travel through a circuit or medium from one point to another. In digital electronics and signal processing, understanding propagation delay is crucial as it can affect the performance and timing of systems, especially in synchronous circuits where timing is critical.

In contrast, noise immunity refers to a system's ability to operate correctly despite the presence of noise, while fan-out defines how many inputs a single output can drive without degrading performance. Therefore, the correct answer to your question is propagation delay.