Final answer:
Handyman Bob's thumb sensations will be transmitted to the central nervous system by afferent (sensory) nerve fibers.
Step-by-step explanation:
The sensations from Handyman Bob's thumb will be transmitted to the central nervous system by afferent (sensory) nerve fibers. Afferent nerve fibers are responsible for carrying nerve impulses from sensory receptors in tissues and organs to the central nervous system. In this case, the sensory receptors in Bob's thumb will send the nerve impulses to the central nervous system, allowing him to experience the pain caused by hitting his thumb with a hammer.