This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Medical, surgical and gynaecological illness complicating pregnancy, Subject name: Gynaecology & Obstetrics
[{'content': 'Which of the following hematological criteria remains unchanged during pregnancy \nSelect and explain. \nA. Blood Volume, B. TIBC, C. MCHC, D. S. ferritin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: MCV increases minimally during pregnancy MCHC remains unchanged Reference: High risk pregnancy Fernando Arias 4th edition Page no: 234', 'role': 'assistant'}]