To make the robot move in a circle, what should be activated?

To make the robot move in a circle, activating only one motor is the correct approach. This method creates a situation where the robot rotates around the stationary point of the wheel that is not functioning, resulting in a circular path.

When one motor is engaged and the other remains inactive, the robot will pivot around the wheel that is still in contact with the ground, enabling the robot to trace a circle. This principle is based on differential steering, where the speed and direction of individual wheels are varied to control the robot's path.

In contrast, operating both motors at equal speeds would cause the robot to move straight ahead rather than in a circle. A custom steering command could potentially lead to circular movement but is not as straightforward as simply using one motor. Engaging all sensors does not directly influence the movement in a circular path; rather, it would be more related to environmental awareness. Thus, only using one motor is the most effective choice for achieving circular motion.