This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of orbit, Lids and lacrimal apparatus, Subject name: Ophthalmology
Ocular muscle involved in Marcus Gun jaw winking phenomenon is - 
Select and explain. 
A. Orbicularis oculi, B. Levator palpebrae, C. Medial rectus, D. Lateral rectus
B: Levator palpebrae
Answer: B: Levator palpebrae 
Explanation: Congenital synkinetic ptosis (Marcus Gunn jaw winking ptosis). In this condition there occurs retraction of the ptotic lid with jaw movements i.e., with stimulation of ipsilateral pterygoid muscle. It is due to the mixing of the fibres of 5th and 3rd cranial nerves. Ref:AK Khurana 4thE pg356