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: Gynaecology & Obstetrics
First histological sign of ovulation is 
Select and explain. 
A. Vacuoles at apical portion of secretory nonciliated cells., B. Cessation of glandular cell mitosis., C. Absent glycoprotein in secretory non ciliated cells., D. Subnuclear vacuoles and pseudostratification in basal portion of glandular epithelium.
D: Subnuclear vacuoles and pseudostratification in basal portion of glandular epithelium.
Answer: D: Subnuclear vacuoles and pseudostratification in basal portion of glandular epithelium. 
Explanation: After ovulation, glycogen accumulates in basal portion of glandular epithelium creating subnuclear vacuoles and pseudostratification.