Transient response refers to the behavior of a system in response to a sudden change in its input or operating conditions. In the case of a feedback system, the output signal is fed back to the input, which can affect the transient response of the system.

The correct answer to the given question is option 'D' - the transient response with a feedback system decays quickly. This means that the system's output quickly settles down to its steady-state value after a disturbance or change in the input.

Explanation:

1. Feedback System:
- A feedback system is a control system where a portion of the output signal is fed back and added to the input signal.
- The feedback signal is used to modify the input and improve the performance of the system.
- In an electrical circuit, feedback can be positive or negative, depending on whether the feedback signal is in phase or out of phase with the input signal.

2. Transient Response:
- The transient response of a system is the temporary response of the system before it reaches its steady-state.
- It represents how the system reacts to changes or disturbances in the input.
- The transient response is characterized by the rise time, peak time, overshoot, settling time, and decay time.

3. Decaying Transient Response:
- In a feedback system, the feedback signal is used to reduce the difference between the desired output and the actual output.
- This helps in minimizing the error and improving the stability and accuracy of the system.
- As a result, the transient response of a feedback system tends to decay quickly.
- The feedback action constantly adjusts the input based on the output, reducing the effect of any initial disturbance or change.

4. Advantages of Quick Decay:
- A quick decay of the transient response indicates that the system is able to recover and stabilize rapidly.
- It minimizes the time taken for the output to settle down to its steady-state value.
- This is desirable in many applications, especially in control systems, where a quick response is necessary to maintain stability and accuracy.
- A feedback system with a quick decay transient response can efficiently correct any errors or disturbances and maintain the desired output.

In conclusion, the transient response of a feedback system decays quickly because the feedback action helps in minimizing the effect of any initial disturbance or change, allowing the system to stabilize rapidly.