This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Structures lying deep to posterior belly of digastric are all except? 
Select and explain. 
A. Retromandibular vein, B. Hypoglossal nerve, C. Hyoglossus muscle, D. Occipital aery
A: Retromandibular vein
Answer: A: Retromandibular vein 
Explanation: Relations of Digastric triangle Superficial Deep (medial) Platysma Mastoid process & sternocleidomastoid Stykohyoid muscle Retromandibular vein & parotid gland Submandibular salivary gland Angle of mandible with medial pterygoid For anterior belly Mylohyoid For posterior belly Transverse process of atlas with superior oblique & rectus capitis lateralis muscle. Hyoglossus muscle Hypoglossal & spinal accessory nerves Occipital, internal & external carotid, facial & lingual aeries Internal jugular vein