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: Medicine
Features of Giardiasis -a) Mal absorptionb) Cyst with 4 nucleic) Trophozoite with four nucleid) Common in hypogammaglobulinemia 
Select and explain. 
A. abd, B. ad, C. bc, D. bcd
A: abd
Answer: A: abd 
Explanation: None