A 35-year-old female presents with a 2-week history of progressive weakness and wasting of the small muscles of her left hand. On examination, she has a claw hand deformity (hyperextension at the metacarpophalangeal joints and flexion at the interphalangeal joints), weakness of finger abduction and adduction, and sensory loss over the medial one-and-a-half fingers and medial aspect of the palm. She reports a history of a pancoast tumour invading the lower trunk of the brachial plexus. Which nerve roots are involved in this injury?