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
O'Sullivan & Mahan criteria is used in :-- 
Select and explain. 
A. Gestational hypertension, B. Gestational diabetes mellitus, C. Rh incompatibility, D. Assessing progress of labour
B: Gestational diabetes mellitus
Answer: B: Gestational diabetes mellitus 
Explanation: Diagnosis of Gestational Diabetes Mellitus (GDM ) is made following a 100 gm glucose load based on criteria laid down by O'Sullivan and Mahan.