d. balance
A person’s vestibular sense helps control balance. In most mammals, the vestibular system is the sensory system that has the leading contribution to the sense of balance and spatial orientation for the purpose of coordinating movement with balance. The vestibular sense reacts to a change in the positioning of the head or when the feet are lifted of the ground. This can also help in regulating a child to keep him/her focused and attentive. Examples of activities that need vestibular input are: somersaults, swinging, hanging upside down form a monkey bar.