**Core Concept**
Central diabetes insipidus is a disorder characterized by the inadequate production of antidiuretic hormone (ADH), also known as vasopressin, which regulates water reabsorption in the kidneys. This condition leads to excessive thirst and polyuria due to the inability to concentrate urine.

**Why the Correct Answer is Right**
The drug of choice for central diabetes insipidus is desmopressin, a synthetic analogue of vasopressin. Desmopressin has a higher affinity for the V2 receptors in the kidneys, which are responsible for water reabsorption, making it a more potent and selective treatment option. It is administered via nasal spray, injection, or orally, and its use helps to regulate water balance and reduce polyuria.

**Why Each Wrong Option is Incorrect**
**Option A:** Vasopressin is a natural analogue of ADH, but it has a shorter duration of action and can cause vasoconstriction, making it less suitable for long-term treatment.
**Option B:** Chlorpropamide, a sulfonylurea, is used in the treatment of diabetes mellitus, not central diabetes insipidus.
**Option C:** Hydrochlorothiazide, a diuretic, would exacerbate the symptoms of central diabetes insipidus by increasing urine production.

**Clinical Pearl / High-Yield Fact**
Desmopressin is a high-yield fact for postgraduate medical students, as it is a specific and effective treatment for central diabetes insipidus, and its use highlights the importance of V2 receptor activation in water reabsorption.

**Correct Answer: D. Desmopressin**