This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
Cycle which is absent in humans is 
Select and explain. 
A. Menstrual cycle, B. Ovarian cycle, C. Hormonal cycle, D. Estrous cycle
D: Estrous cycle
Answer: D: Estrous cycle 
Explanation: .