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
A pregnant lady with aids complains of diahorrea and stool examination shows acid fast positive cysts. She has infection with: 
Select and explain. 
A. Isospora, B. Giardia, C. Entameob a, D. Microspora
A: Isospora
Answer: A: Isospora 
Explanation: Isospora