This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
All the drugs are used in the treatment of Giardiasis except: 
Select and explain. 
A. Nitazoxanide, B. Metronidazole, C. Tinidazole, D. Diloxanide furoate
D: Diloxanide furoate
Answer: D: Diloxanide furoate 
Explanation: Treatment options for Giardiasis:metronidazole (250 mg tds for 5 days)tinidazole (2 g once by mouth)nitazoxanide (500 mg bd for 3 days)paromomycin, an oral aminoglycosideDiloxanide furoate is a lumenal amebicide(ref:Harrison's 18/e p1731, 17/e p1313)