Answer:
B
Step-by-step explanation:
B) Amebic dysentery
A serum antibody titer for Entamoeba histolytica is used to assess and diagnose amebic dysentery, which is caused by this parasite. It helps detect the presence of specific antibodies in the blood, indicating an active or previous infection with Entamoeba histolytica. Giardiasis (option A) is caused by the parasite Giardia lamblia and is diagnosed differently, typically through stool tests. Echinococcosis (option C) is caused by tapeworms of the Echinococcus genus and is also diagnosed differently. Option D, "Tapeworm infection," is a general term that can refer to various tapeworm species and is not typically diagnosed through a serum antibody titer for Entamoeba histolytica.