## Core Concept
Imipenem is a carbapenem antibiotic with a broad spectrum of activity against both Gram-positive and Gram-negative bacteria. It is particularly noted for its effectiveness against bacteria that produce beta-lactamases. Imipenem acts by inhibiting cell wall synthesis in bacteria.

## Why the Correct Answer is Right
Imipenem is effective against a wide range of bacteria, including many strains of Gram-negative bacteria that are resistant to other antibiotics due to their ability to produce beta-lactamases. This is because imipenem is stable against degradation by most beta-lactamases. Among the options provided, without specific details on A, B, C, and D, we can infer based on general knowledge that imipenem's broad-spectrum activity includes many Gram-negative rods, some Gram-positive cocci, and anaerobes.

## Why Each Wrong Option is Incorrect
- **Option A:** Without specific details, we cannot directly address why this option might be incorrect, but generally, imipenem's spectrum does not include MRSA (methicillin-resistant Staphylococcus aureus) or some extended-spectrum beta-lactamase (ESBL) producers that are resistant to carbapenems.
- **Option B:** Similarly, without specifics, if this option represents an organism typically resistant to imipenem (like some carbapenem-resistant Enterobacteriaceae), it would be incorrect.
- **Option C:** This could potentially represent an organism susceptible to imipenem, but without specifics, it's hard to confirm.
- **Option D:** If this option represents Pseudomonas aeruginosa, imipenem is indeed active, but resistance can occur.

## Clinical Pearl / High-Yield Fact
A key point to remember is that imipenem is often used in combination with cilastatin, which inhibits the renal enzyme dehydropeptidase-1. This enzyme can metabolize imipenem, reducing its effectiveness. The combination of imipenem and cilastatin helps to prevent this renal metabolism, maintaining therapeutic levels of imipenem.

## Correct Answer: C.