**Core Concept:** McCune-Albright syndrome is a rare, constitutional disorder characterized by post-natal polyostotic fibrous dysplasia, café-au-lait macules, and endocrinopathies (typically growth hormone, adrenocorticotropic hormone, and gonadotropin).

**Why the Correct Answer is Right:** McCune-Albright syndrome is caused by a point mutation in the GNAS1 gene which encodes the alpha subunit of the stimulatory G protein (Gs alpha). This leads to increased cAMP production and subsequent cellular effects, causing fibrous dysplasia, café-au-lait macules, and endocrinopathies.

**Why Each Wrong Option is Incorrect:**

A. **Not a feature of McCune-Albright syndrome:** This option is incorrect because it describes a different condition, not related to the GNAS1 gene mutation or the features of McCune-Albright syndrome.

B. **Not a feature of McCune-Albright syndrome:** Similar to option A, this option does not relate to the underlying genetic cause (GNAS1 gene mutation) or the clinical manifestations of the syndrome.

C. **Not a feature of McCune-Albright syndrome:** This option is incorrect because it describes a benign tumor (benign fibrous dysplasia) rather than a syndrome characterized by a genetic mutation.

D. **Not a feature of McCune-Albright syndrome:** This option is incorrect because it describes a benign tumor (adenoma) that is not a part of McCune-Albright syndrome manifestations.

**Clinical Pearl:** McCune-Albright syndrome is a clinically recognizable condition with specific features that help in making the diagnosis, including postnatal fibrous dysplasia, café-au-lait macules, and endocrinopathies. Awareness of these features can guide clinicians in making a correct diagnosis and managing the patients appropriately.