## Core Concept
A prodrug is a medication or compound that, after administration, is metabolized into a pharmacologically active drug. Prodrugs are often used to improve bioavailability, reduce side effects, or to make the active drug more soluble. This concept is crucial in pharmacology as it relates to drug design, delivery, and efficacy.

## Why the Correct Answer is Right
The correct answer involves identifying which of the listed compounds are prodrugs. A well-known example of a prodrug is **codeine**, which is metabolized into morphine, and **heroin** (diacetylmorphine), which is metabolized into morphine as well. Another classic example is **chloramphenicol**, but more notably, **sulfasalazine** is a prodrug used in the treatment of ulcerative colitis, which is metabolized into sulfapyridine and 5-aminosalicylic acid (5-ASA), the latter being the active component.

## Why Each Wrong Option is Incorrect
- **Option A:** Without specific details on the compound, it's hard to assess its prodrug status directly. However, if it's not recognized as a prodrug, it would be incorrect.
- **Option B:** Similarly, without specifics, if this option is not a known prodrug, it would be incorrect.
- **Option D:** This option would be incorrect if it does not represent a prodrug.

## Clinical Pearl / High-Yield Fact
A memorable point is that **sulfasalazine** is a prodrug that gets metabolized into **5-aminosalicylic acid (5-ASA)**, which is crucial for its therapeutic effect in treating ulcerative colitis. This is a high-yield fact because it's a commonly tested drug in pharmacology and its mechanism of action as a prodrug is significant.

## Correct Answer: C.