## Core Concept
Glibenclamide (also known as glyburide) and chlorpropamide are both sulfonylureas used in the management of type 2 diabetes mellitus (DM). They work by stimulating insulin release from the pancreatic beta cells. However, they have different pharmacokinetic profiles and side effect profiles, which influence their preference in clinical practice.

## Why the Correct Answer is Right
Chlorpropamide has a higher incidence of causing **hyponatremia** due to its antidiuretic hormone (ADH)-like effect, leading to water retention and potentially severe hyponatremia. This side effect is more pronounced with chlorpropamide compared to glibenclamide.

## Why Each Wrong Option is Incorrect
* **Option A:** While both drugs can cause hypoglycemia, this is not more specifically associated with chlorpropamide over glibenclamide; it's a class effect of sulfonylureas.
* **Option B:** Although sulfonylureas can cause weight gain, this is not a reason chlorpropamide is specifically avoided in favor of glibenclamide.
* **Option C:** This option is correct but not provided; however, based on the context, we know chlorpropamide's side effect profile includes a higher risk of **hyponatremia**.
* **Option D:** Not provided, but presumably another incorrect option.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that chlorpropamide's association with **hyponatremia** makes glibenclamide a preferred option when sulfonylurea therapy is indicated, especially in patients at risk for or with a history of hyponatremia.

## Correct Answer: C. Hyponatremia.