Which sentence is punctuated correctly? *

A. A stirrup-shaped bone in the ear, the stapes is the smallest bone in the human body
B. A stirrup-shaped bone in the ear, the stapes, is the smallest bone in the human body
C. A stirrup-shaped bone in the ear; the stapes is the smallest bone in the human body
D. A stirrup-shaped bone in the ear; the stapes, is the smallest bone in the human body