A 65-year-old male with a history of polio presents with weakness in his left leg. He has difficulty walking and demonstrates a foot drop. Which orthotic device would be most appropriate for him?

A Ankle-Foot Orthosis (AFO) B Knee-Ankle-Foot Orthosis (KAFO) C Spinal Brace D Hip-Knee-Ankle-Foot Orthosis (HKAFO)