This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CVS Embryology, Subject name: Anatomy
The sinus occupying coronary sulcus is derived from which of the following? 
Select and explain. 
A. Truncus aeriosus, B. Bulbus cordis, C. Primitive ventricle, D. Sinus venosus
D: Sinus venosus
Answer: D: Sinus venosus 
Explanation: The coronary sinus occupies coronary sulcus. The coronary sinus is derived from theleft horn of sinus venosus.