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
Appendix of testis is remnant of ? 
Select and explain. 
A. Mesonephric duct, B. Mesonephric tubules, C. Wolffian duct, D. Mullerian duct
D: Mullerian duct
Answer: D: Mullerian duct 
Explanation: Mullerian duct