Final answer:
The answer is option b) C7-C8-T1; Affects the lower trunk, which refers to Klumpke's paralysis, a form of brachial plexus injury specifically impacting the nerves of the lower trunk.
Step-by-step explanation:
The subject of the question is related to a type of brachial plexus injury known as Erb's palsy and Klumpke's paralysis, each affecting different parts of the arm due to nerve damage. Erb's palsy typically involves roots C5-C6-C7 and affects the upper trunk, leading to a loss of movement and/or feeling in the arm. Klumpke's paralysis, on the other hand, generally affects roots C8-T1 and impacts the lower trunk, potentially causing a claw-like hand due to paralysis of the intrinsic muscles of the hand. The correct answer to the student's question is option b) C7-C8-T1; Affects lower trunk.