## Core Concept
The question tests the knowledge of antibiotics effective against *Pseudomonas aeruginosa*, a type of bacteria that can cause infections, particularly in immunocompromised individuals or those with cystic fibrosis. *Pseudomonas* infections are notorious for their resistance to many antibiotics. The correct answer must be an antibiotic known for its efficacy against this pathogen.

## Why the Correct Answer is Right
Ceftazidime is a third-generation cephalosporin antibiotic with a broad spectrum of activity, including effectiveness against *Pseudomonas aeruginosa*. It works by inhibiting bacterial cell wall synthesis, ultimately leading to cell lysis and death. Ceftazidime is often used in severe infections, including those caused by *Pseudomonas*, especially in hospitalized patients.

## Why Each Wrong Option is Incorrect
* **Option A:** While certain penicillins, especially those with a broad spectrum like piperacillin (often combined with tazobactam), can be effective against *Pseudomonas*, the option provided does not specify a known anti-*Pseudomonas* penicillin.
* **Option B:** This option does not provide a recognizable antibiotic name effective against *Pseudomonas*.
* **Option D:** Similarly, this option lacks a specific antibiotic name known for its efficacy against *Pseudomonas* infections.

## Clinical Pearl / High-Yield Fact
A key point to remember is that when treating *Pseudomonas* infections, antibiotics such as ceftazidime, ciprofloxacin, imipenem, and piperacillin-tazobactam are considered effective options. The choice of antibiotic may depend on susceptibility testing and the site of infection.

## Correct Answer Line
**Correct Answer: C. Ceftazidime**.