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: Microbiology
Giardiasis is best diagnosed by: 
Select and explain. 
A. CFT, B. Presence of both cysts and trophozoites in stools, C. Presence of cysts only, D. Haemaglutination
B: Presence of both cysts and trophozoites in stools
Answer: B: Presence of both cysts and trophozoites in stools 
Explanation: Presence of both cysts and trophozoites in stools