## Core Concept
The question tests knowledge of microbial contamination, specifically bacteria that can contaminate antiseptic solutions like Dettol and Savlon. These solutions are commonly used for wound care and skin disinfection. The bacteria in question likely have a unique characteristic allowing them to survive in environments that would typically be inhospitable due to the antiseptic properties of these solutions.

## Why the Correct Answer is Right
*Pseudomonas aeruginosa* is known for its ability to contaminate various substances, including antiseptic solutions. This bacterium is gram-negative, aerobic, and has a remarkable ability to adapt to different environments. It can produce biofilms, which provide protection against antimicrobial agents. *Pseudomonas aeruginosa* is an opportunistic pathogen that can cause infections in individuals with compromised immune systems or damaged tissues.

## Why Each Wrong Option is Incorrect
- **Option A:** While certain species of *Bacillus* can form highly resistant spores, they are not typically associated with the contamination of antiseptic solutions like Dettol and Savlon.
- **Option B:** *Escherichia coli* is a common cause of infections but is less commonly associated with the contamination of antiseptics compared to *Pseudomonas aeruginosa*.
- **Option D:** *Staphylococcus aureus* is a common cause of skin infections but is not specifically known for contaminating antiseptic solutions.

## Clinical Pearl / High-Yield Fact
A key point to remember is that *Pseudomonas aeruginosa* can develop resistance to many antimicrobial agents, making it a significant concern in healthcare settings. Its ability to contaminate antiseptic solutions highlights the importance of proper storage and handling of these products to prevent microbial growth.

## Correct Answer Line
**Correct Answer: C. Pseudomonas aeruginosa.**