## **Core Concept**
The question tests knowledge of antimicrobials and their spectrum of activity, specifically against *Pseudomonas aeruginosa*, a Gram-negative bacterium known for its resistance to many antibiotics. Antipseudomonal antibiotics are crucial in treating infections caused by this organism, particularly in healthcare-associated 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 and provides activity against *Pseudomonas aeruginosa*. Piperacillin/tazobactam is one of the antipseudomonal penicillins, making it effective against *P. aeruginosa*.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is blank and thus cannot be evaluated.
- **Option B:** This option is also blank and cannot be assessed.
- **Option D:** This option is blank as well, making it impossible to provide a reason for its incorrectness.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that when treating infections suspected or confirmed to be caused by *Pseudomonas aeruginosa*, antipseudomonal antibiotics such as piperacillin/tazobactam, ceftazidime, cefepime, imipenem, meropenem, and ciprofloxacin should be considered. The choice of antibiotic may depend on susceptibility testing and patient-specific factors.

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