**Core Concept**
Cysticercosis is a parasitic infection caused by the larval stage of a tapeworm, specifically *Taenia solium*, which invades the muscles and other tissues of the human body. This condition is a significant public health concern in many developing countries.

**Why the Correct Answer is Right**
The correct answer is related to the life cycle of *Taenia solium*. When an individual ingests contaminated food or water, the tapeworm's eggs hatch in the gastrointestinal tract and release oncospheres, which penetrate the intestinal wall and enter the bloodstream. The oncospheres are then carried to various organs and tissues, where they develop into cysticerci, the larval stage of the tapeworm. This process leads to the formation of cysticerci in the muscles and other tissues, resulting in cysticercosis.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify the causative agent of cysticercosis. While other parasites may cause similar conditions, *Taenia solium* is the primary cause of cysticercosis.
* **Option B:** This option is incorrect because it is a different type of parasitic infection caused by a different organism. Echinococcosis, or hydatid disease, is caused by the larval stage of the tapeworm *Echinococcus*.
* **Option C:** This option is incorrect because it is a different type of infection altogether. Histoplasmosis is a fungal infection caused by *Histoplasma capsulatum*, which is not related to cysticercosis.

**Clinical Pearl / High-Yield Fact**
Cysticercosis can be diagnosed through imaging studies, such as CT or MRI scans, which show the presence of cysticerci in the muscles and other tissues. Treatment typically involves antiparasitic medications, such as albendazole or praziquantel, which can help eliminate the infection.

**Correct Answer: D. Taenia solium**