## **Core Concept**
The question tests the knowledge of antimicrobial agents, specifically those effective against *Pseudomonas aeruginosa*, a type of gram-negative bacteria known for its resistance to many antibiotics. *Pseudomonas* infections are common in immunocompromised patients and those with cystic fibrosis. Effective treatments are crucial for managing these infections.

## **Why the Correct Answer is Right**
The correct answer, **C. Piperacillin/Tazobactam**, is a combination of a broad-spectrum beta-lactam antibiotic (piperacillin) and a beta-lactamase inhibitor (tazobactam). This combination extends the spectrum of piperacillin to include beta-lactamase-producing bacteria, including many strains of *Pseudomonas aeruginosa*. Piperacillin/tazobactam is commonly used in clinical settings for treating complicated infections, including those caused by *Pseudomonas*.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is blank and cannot be evaluated.
- **Option B:** This option is blank and cannot be evaluated.
- **Option D:** This option is blank and cannot be evaluated.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that when treating *Pseudomonas* infections, it's essential to use antibiotics that are known to be effective against this pathogen. *Pseudomonas aeruginosa* is notorious for its intrinsic resistance to many antibiotics and its ability to develop resistance to multiple agents. Therefore, options like **C. Piperacillin/Tazobactam**, along with other anti-pseudomonal antibiotics such as ceftazidime, cefepime, imipenem, meropenem, and aminoglycosides, are critical in the antimicrobial armamentarium.

## **Correct Answer:** . Piperacillin/Tazobactam