While cutting wood for his daughter's playhouse, Lee accidentally severed his finger. Fortunately, Lee was quickly rushed to the hospital where his finger was successfully reattached. Lee was eventually able to regain some function and feeling in his once-severed appendage. Which of the following helped to repair the nerve fibers that give Lee the ability to regain function and feeling in his finger?

• A. Glial cells
• B. Schwann cells
• C. Myelin
• D. Oligodendrocytes