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 trabeculated pa of the right ventricle is derived from which of the following? 
Select and explain. 
A. Truncus aeriosus, B. Bulbus cordis, C. Primitive ventricle, D. Primitive atrium
C: Primitive ventricle
Answer: C: Primitive ventricle 
Explanation: C. The trabeculated pa / rough pa /anterior pa of the right ventricle is derived from the primitive ventricle.