An OT provides caregiver training to the spouse of an individual with cerebellar cortical degeneration. The focus of the session is on community mobility using a wheelchair. The individual is dependent upon the spouse's assistance for mobility. Which of the following is most effective for the therapist to recommend the spouse to do when descending a steep grade? a. Tilt the wheelchair backward to its gravitational balance point and then go down backward b. Go down backward with all wheelchair wheels maintaining contact with the ground surface c. Push forward as on flat surfaces but lean body back for extra drag d. Tilt the wheelchair backward to its gravitational balance point and then go down forward