Regarding the Repair of the Central Nervous System,which of the Following

Regarding the repair of the central nervous system,which of the following statements is FALSE?

A) Although animal studies have been conducted, no human trials involving the repair of damaged spinal cords have been undertaken yet.
B) Scientists have partially repaired cut spinal cords in rats.
C) Currently, a serious injury to the brain or spinal cord is usually permanent.
D) Stem cells have been injected into the gap in the spinal cord to form a cellular bridge to repair the damaged spinal cord.