Task: Class Definition Understanding (ontology: Sciences/Biology)

Which of the following definitions best describes 'auditory bulla'?

A. A hollow bony structure on the ventral, posterior portion of the skull of placental mammals that encloses parts of the middle and inner ear. In most species, it is formed by the tympanic part of the temporal bone.
B. Subdivision of the cleithrum that extends along the anterior edge of the suprascapula.
C. Projection on the lateral side of proximal part of the ulna.
D. A wavy crest externally on the tympanic bone of cetaceans.

Answer: A hollow bony structure on the ventral, posterior portion of the skull of placental mammals that encloses parts of the middle and inner ear. In most species, it is formed by the tympanic part of the temporal bone.