Which muscle is associated with finger abduction and its respective spinal root innervation?

The abductor digiti minimi is the correct muscle associated with finger abduction, particularly for the fifth digit (little finger). It is innervated by the ulnar nerve, which arises from the spinal roots C8 and T1. This nerve plays a crucial role in facilitating movement in the intrinsic muscles of the hand, contributing to the abduction of the little finger away from the fourth digit, thereby increasing the functionality of grasping and releasing objects.

Understanding the specific spinal root connections is important in clinical assessments, as it can help localize nerve injuries. In this case, knowing that the abductor digiti minimi is innervated by C8 and T1 allows for pinpointing potential ulnar nerve issues at or near these spinal levels.

The other options involve muscles that either do not primarily function in finger abduction or have different spinal root innervations, which highlights the specificity needed when discussing muscle functions and nerve innervation in the context of hand movements.