## **Core Concept**
The question tests the knowledge of selective media used in microbiology for the isolation of specific bacteria, in this case, *Vibrio*. Selective media are agar plates that inhibit the growth of certain types of bacteria while allowing others to grow, often based on specific nutrients or antibiotics.

## **Why the Correct Answer is Right**
TCBS (Thiosulfate-citrate-bile salts-sucrose) agar is specifically designed for the isolation of *Vibrio* species, including *Vibrio cholerae*. This medium is selective because it contains:
- **Thiosulfate** as a source of sulfur,
- **Citrate** as a carbon source,
- **Bile salts** to inhibit the growth of Gram-positive bacteria and some Gram-negative bacteria,
- **Sucrose** as a fermentable carbohydrate.

*Vibrio* species can ferment sucrose, producing colonies with distinctive appearances on TCBS agar.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While not specified, common media like Blood Agar or Chocolate Agar are not selective for *Vibrio* as they support the growth of a wide range of bacteria.
- **Option B:** MacConkey agar is selective for Gram-negative bacteria but is not specific for *Vibrio*.
- **Option D:** Mannitol Salt Agar is selective for *Staphylococcus* species, particularly *Staphylococcus aureus*, and is not used for *Vibrio*.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that TCBS agar is not only selective but also differential, allowing for the differentiation of *Vibrio* species based on their ability to ferment sucrose. *Vibrio cholerae* colonies on TCBS are typically yellow due to sucrose fermentation.

## **Correct Answer:** C. TCBS Agar.