Which of the following statements about the vestibular system is true?

The vestibular system is primarily responsible for detecting gravity and movement, making the statement that it consists of structures that detect these factors true. The vestibular system is composed of the inner ear structures, including the semicircular canals and the otolith organs, which work together to sense the position of the head in space and changes in motion. This detection helps the body maintain balance and posture during various activities.

While the vestibular system plays a critical role in balance, it is not the sole system responsible for maintaining it, as other sensory inputs, such as visual information and proprioceptive feedback from the muscles and joints, also contribute. Thus, stating that it is solely responsible for balance does not capture the integrative nature of how balance is achieved. Additionally, although the vestibular system does interact with visual inputs, it can function independently of them, and therefore it does not "rely" solely on visual stimuli for motion detection. Furthermore, the vestibular system is not involved in processing auditory stimuli, which is the primary function of the auditory system.