**Core Concept**
Taenia saginata is a tapeworm species that primarily infects humans and is a causative agent of bovines (cattle, buffalo, etc.). The intermediate host for Taenia saginata is a herbivore, and the final host is humans who consume undercooked beef contaminated with Taenia tapeworm eggs.

**Why the Correct Answer is Right**
The correct answer is **D**: Humans consume undercooked beef contaminated with Taenia saginata eggs, which then develop into cysticerci in the herbivore intermediate host, specifically cattle. The cysticerci mature into adult tapeworms in the human intestine when consumed, causing Taenia saginata infection.

**Why Each Wrong Option is Incorrect**
A. **Option A - Humans (Homo sapiens)**: Humans are the definitive host, not the intermediate host. Humans acquire the infection through consumption of contaminated beef, not through an intermediate host.
B. **Option B - Larvae (Cysticercus cellulosae)**: This refers to the stage in the intermediate host, not the definitive host. Cysticercus cellulosae is the larval form of Taenia saginata found in cattle.
C. **Option C - Cattle**: Cattle serve as the intermediate host for Taenia saginata, but the correct answer is D, as it identifies humans as the definitive host.
D. **Option D - Humans**: Humans serve as the definitive host by consuming contaminated beef, leading to infection with Taenia saginata.

**Clinical Pearl**
Understanding the life cycle of Taenia saginata is crucial for preventing this infection. To avoid Taenia saginata infection, ensure beef is thoroughly cooked before consumption and practice hygiene when handling raw or undercooked meat.