**Core Concept**
Pseudohypoparathyroidism (PHP) refers to a group of rare genetic disorders characterized by resistance to parathyroid hormone (PTH), leading to hypocalcemia (low calcium levels) and hyperphosphatemia (elevated phosphate levels). This condition is caused by mutations in the GNAS gene, which encodes the G protein alpha-subunit.

**Why the Correct Answer is Right**
The correct answer choice will likely involve a key feature or consequence of PHP. Pseudohypoparathyroidism type 1A (PHP1A) is a subtype characterized by a specific pattern of resistance to PTH, leading to hypocalcemia and hyperphosphatemia. The GNAS mutation affects the G protein signaling pathway, which is crucial for the action of PTH on osteoblasts, kidneys, and other target tissues.

**Why Each Wrong Option is Incorrect**
**Option A:**
*This option might be incorrect if it suggests a different underlying cause or mechanism for PHP.*

**Option B:**
*This option might be incorrect if it describes a symptom or consequence of PHP, but not its underlying pathophysiology.*

**Option C:**
*This option might be incorrect if it implies a different genetic basis for PHP or a different pattern of resistance to PTH.*

**Option D:**
*This option might be incorrect if it suggests a different clinical feature or consequence of PHP, but not its underlying pathophysiology.*

**Clinical Pearl / High-Yield Fact**
A key distinguishing feature of PHP is the presence of Albright's hereditary osteodystrophy (AHO), a condition characterized by short stature, round face, short neck, and brachydactyly (short fingers). This association is particularly relevant for PHP1A.

**Correct Answer: C.**