Final answer:
The term "hydatid sand" refers to the contents of hydatid cysts caused by the tapeworm Echinococcus granulosus, which is responsible for hydatid disease.
Step-by-step explanation:
Hydatid Sand and Hydatid Disease
The term “hydatid sand” refers to the granular content found in hydatid cysts, which are caused by the tapeworm Echinococcus granulosus.
This tapeworm is known for causing hydatid disease or cystic echinococcosis, a serious infection that occurs when the tapeworm's larval stages form cysts in the organs of the intermediate host.
Humans can become accidental intermediate hosts by ingesting E. granulosus eggs, leading to the development of hydatid cysts in organs like the liver and lungs.
The options listed in the question correspond to different tapeworm species. A. Taenia saginata and C.
Diphyllobothrium latum can cause taeniasis upon ingestion of undercooked meat from cows and fish, respectively. D. Hymenolepis nana is another species of tapeworm.
However, it is B. Echinococcus granulosus that is associated with the formation of hydatid cysts and the presence of “hydatid sand” inside these cysts.