Which structure does Meckel's cartilage primarily contribute to in the adult?

Correct answer: A. Sphenomandibular ligament

• A. Correct. Meckel's cartilage (1st branchial arch) regresses and contributes to the sphenomandibular ligament. Parts also ossify to form the malleus and incus (middle ear ossicles).
• B. The mandible forms by intramembranous ossification around Meckel's cartilage — the cartilage itself does not become mandibular bone.
• C. While the incus and malleus partly derive from Meckel's cartilage, the primary recognized contribution tested on boards is the sphenomandibular ligament.
• D. The hyoid bone is derived from the 2nd and 3rd branchial arch cartilages, not Meckel's cartilage.