Final answer:
The free edge is the part of the nail plate that extends over the tip of the finger or toe. Therefore, the correct option is B.
Step-by-step explanation:
The part of the nail plate that extends over the tip of the finger or toe is the Free edge. The free edge is the exposed, distal portion of the nail plate that extends beyond the fingertip or toe tip. It is the visible part of the nail that can be trimmed and shaped.
The lunula (a) is the pale, crescent-shaped area at the base of the nail. The cuticle (c) is the thin layer of skin at the base of the nail that protects the matrix. The nail bed (d) is the skin beneath the nail plate. The free edge is the external, unattached portion of the nail that is often the focus of grooming and maintenance.
Therefore, the correct option is B.