## Core Concept
Löffler's medium is a type of enriched medium used in microbiology for the isolation and cultivation of certain bacteria, particularly *Corynebacterium diphtheriae*. It is an example of a selective medium that supports the growth of specific pathogens.

## Why the Correct Answer is Right
Löffler's medium consists of a mixture of horse serum, glucose, and nutrient broth, which provides a nutrient-rich environment. The medium is specifically designed to support the growth of *Corynebacterium diphtheriae*, the causative agent of diphtheria. The high serum content helps in the rapid growth of this organism.

## Why Each Wrong Option is Incorrect
* **Option A:** This option is incorrect because it does not accurately represent Löffler's medium.
* **Option B:** This option is incorrect because it does not correspond with the composition or purpose of Löffler's medium.
* **Option D:** This option is incorrect because it does not accurately describe Löffler's medium.

## Clinical Pearl / High-Yield Fact
A key point to remember is that Löffler's medium is used not only for isolation but also for the preliminary identification of *Corynebacterium diphtheriae* due to its characteristic growth pattern and metachromatic granules that can be stained and observed microscopically.

**Correct Answer: C. Loffler's medium**.