Final answer:
The child with a scissoring gait and use of forearm crutches most likely has spastic diplegia, a common type of cerebral palsy affecting the lower limbs.
Step-by-step explanation:
Based upon the observation of a child with a scissoring gait, walking with forearm crutches due to cerebral palsy, the most likely type of cerebral palsy he has is spastic diplegia. Spastic diplegia is a form of cerebral palsy that primarily affects the lower extremities, leading to muscle hypertonia or increased muscle tone, and can cause a scissoring gait where the legs cross midline resembling the action of scissors. This type of gait is a classic symptom of spastic diplegia caused by damage to the motor areas in the brain that affect the lower limbs. Forearm crutches are often used to support mobility in individuals with spastic diplegia because they can improve balance and walking patterns.