This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hemolytic Anemias: Basic concepts and classification, Subject name: Pathology
Which of the following is the best test for diagnosis of paroxysmal nocturnal hemoglobinuria? 
Select and explain. 
A. Sucrose lysis test, B. Ham test, C. Flow cytometry, D. Bone marrow aspiration
C: Flow cytometry
Answer: C: Flow cytometry 
Explanation: - Best investigation for diagnosing PNH - Flaer flow cytometry - Biphenotypic cells are seen - Other investigations used are: Ham's acidified serum test Sucrose lysis test