Neuroanatomy USMLE Step 1 Practice Question

A 52-year-old woman presents with severe pain beneath her left index fingernail. Vital signs show BP 128/82 mmHg, HR 88/min, RR 16/min, temperature 37.2°C, and SpO2 98% on room air. Physical examination reveals a 0.2 cm subungual nodule with tenderness to palpation; no erythema or drainage noted. X-ray shows no bony involvement. She denies recent trauma or systemic symptoms. Local anesthetic block to a branch of which nerve would most effectively provide anesthesia for surgical excision?