Final answer:
The gyroscope in a mobile device detects rotational motion and allows the device to shift its display orientation. It works in tandem with the accelerometer, which can also sense device orientation.
Step-by-step explanation:
The feature on a mobile device that is responsible for shifting the device display orientation when you rotate the device is known as the gyroscope. A gyroscope can sense rotational motion and changes in orientation, which it uses to adjust the screen accordingly. However, another similar feature, the accelerometer, is often used in tandem with the gyroscope to detect orientation changes. While the accelerometer can detect acceleration in any direction, it can also sense the static force of gravity, making it useful for determining the angle at which the device is being held. As a result, the correct answer is B. Gyroscope, with the caveat that both sensors work together to provide a smooth orientation experience.