Final answer:
Feedback control in engineering requires sensing the output of a process and adjusting accordingly to maintain the desired system performance, which is option d) Output and adjust accordingly.
Step-by-step explanation:
The question relates to the concept of feedback control systems which are an essential part of engineering, particularly in control engineering and automation. Feedback control systems are designed to automatically adjust their action in response to the system's output. The correct answer to the question 'Feedback control requires being able to sense the:' is d) Output and adjust accordingly. This means that the system senses the output of a process and compares it to a desired set point. If there is a difference, known as the error signal, the control system will take action to reduce this error by adjusting its input to the process accordingly. Examples of feedback control systems include a home heating system that adjusts the furnace operation based on the temperature of the home or a cruise control system in a car that adjusts throttle input based on vehicle speed.