**Core Concept**
Desmopressin is a synthetic analogue of vasopressin, used to treat conditions like diabetes insipidus and hemophilia A. It works by stimulating the release of **von Willebrand factor (VWF)** and **factor VIII** from endothelial cells. This process is mediated by specific receptors.

**Why the Correct Answer is Right**
Desmopressin acts on **V2 receptors**, which are found on the surface of endothelial cells. Stimulation of these receptors leads to an increase in the release of VWF and factor VIII, which are essential for blood clotting. The V2 receptors are coupled to **adenylyl cyclase**, which increases the production of **cAMP**, a secondary messenger that triggers the release of VWF and factor VIII.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct receptor type.
**Option B:** This option is incorrect because it refers to a different type of receptor that is not involved in the release of VWF and factor VIII.
**Option C:** This option is incorrect because it is not related to the mechanism of action of desmopressin.
**Option D:** This option is incorrect because it is not a valid receptor type for desmopressin.

**Clinical Pearl / High-Yield Fact**
Desmopressin is used to treat hemophilia A by increasing the levels of factor VIII, and it is also used to treat diabetes insipidus by increasing water reabsorption in the kidneys. Remember that desmopressin has a longer duration of action compared to vasopressin.

**Correct Answer:** D. V2 receptors