**Nephrogenic Diabetes Insipidus (NDI) Core Concept**
Nephrogenic diabetes insipidus (NDI) is a condition characterized by the kidneys' inability to concentrate urine in response to antidiuretic hormone (ADH) due to a defect in the collecting ducts' ability to respond to ADH. This results in excessive water loss and polyuria.

**Why the Correct Answer is Right**
In NDI, the kidneys are unable to respond to ADH due to a defect in the vasopressin V2 receptor (V2R) or an impairment in the downstream signaling pathways. The V2R is responsible for the insertion of aquaporin-2 water channels into the apical membrane of collecting duct cells, allowing water reabsorption. In NDI, this process is disrupted, leading to continued water loss. The condition can be caused by genetic mutations, lithium or demeclocycline therapy, or other acquired factors.

**Why Each Wrong Option is Incorrect**
* **Option A:** This statement is incorrect because NDI is indeed characterized by an inability to concentrate urine in response to ADH.
* **Option B:** This statement is incorrect because NDI is typically associated with a defect in the collecting ducts' ability to respond to ADH, not a problem with ADH production or release.
* **Option C:** This statement is incorrect because NDI is not primarily caused by a deficiency of ADH, but rather a defect in the collecting ducts' response to ADH.

**Clinical Pearl / High-Yield Fact**
A key distinguishing feature of NDI from central diabetes insipidus (CDI) is the presence of normal ADH levels in NDI patients, whereas CDI patients have low or undetectable ADH levels.

**Correct Answer: D**