Final answer:
C. Parasite
Parasitic infections are diagnosed by identifying the adult worm or the eggs in a specimen, primarily through microscopic examination of stool, immunoassays, or imaging techniques. This is specific to parasitic helminths, such as tapeworms, guinea worms, and hookworms.
Step-by-step explanation:
The diagnosis of infections caused by the presence of adult worm or their eggs in a specimen is specifically related to parasitic infections. Helminths, or multicellular parasitic worms, are a common subject of such diagnoses. These species are not considered microorganisms due to their size but are a focus in the field of microbiology because their diseases involve microscopic eggs and larvae that can be found in stool samples, blood, or tissue samples. Examples of helminthic parasites include beef tapeworm (Taenia saginata), guinea worm (Dracunculus medinensis), and hookworms. Diagnostic techniques might include microscopic observation of stool for eggs, immunoassay tests to identify specific species, and in some cases, imaging techniques like X-rays or ultrasounds.