The Primary Treatment for Giardiasis (Infection with Giardia), as Well

Multiple Choice

The primary treatment for giardiasis (infection with Giardia) , as well as for trichomoniasis (infection with Trichomonas vaginalis) and for amoebic dysentery (infection with Entamoeba histolytica) , is a drug marketed as Flagyl (generic name is metronidazole) . The drug also kills anaerobic gut bacteria. Consequently, which of these are cues that Flagyl's mode of action has nothing to do with attacking or disabling the parasites' flagella, as the drug's name might imply?
1) It would also harm the flagellated lining of the human intestine.
2) Entamoeba possesses pseudopods, not flagella, yet it is killed by Flagyl.
3) Prokaryotic flagella and eukaryotic flagella are radically different from each other and unlikely to be harmed by the same chemical.
4) Not all anaerobic gut bacteria possess flagella, yet it kills these bacteria.

A) 1 and 2
B) 1 and 3
C) 2 and 3
D) 1, 2, and 4
E) 2, 3, and 4