The answer is letter b. stapes. >The malleus<span> is the outermost and largest of the three small bones in the middle ear, and reaches an average length of about eight millimeters in the typical adult. ></span>The stapes<span> is a bone in the middle ear of humans and other mammals involved in the conduction of sound vibrations to the inner ear. </span><span>>The incus the middle one of a chain of three small bones in the middle ear of humans and other mammals </span>>The tympanum<span> is an external </span>hearing<span> structure in animals such as </span><span>frogs</span>
