Final answer:
Option (a), The incisive branch of the inferior alveolar nerve supplies sensation to the lower lip and chin.
Step-by-step explanation:
The incisive branch of the inferior alveolar nerve is responsible for supplying sensation to the anterior teeth. It is a continuation of the inferior alveolar nerve that emerges from the mandibular foramen and runs through a tunnel in the body of the mandible, providing sensory innervation to the lower teeth. This nerve then terminates as the mental nerve, which exits via the mental foramen and supplies sensation to the lower lip and chin.