**Core Concept**
Achondroplasia is the most common form of short-limbed dwarfism, characterized by a mutation in the fibroblast growth factor receptor 3 (FGFR3) gene. This mutation leads to impaired bone growth, resulting in characteristic physical features.

**Why the Correct Answer is Right**
The mode of inheritance for achondroplasia is autosomal dominant. This means that a single copy of the mutated gene is sufficient to cause the condition. When an individual with achondroplasia has children, each child has a 50% chance of inheriting the mutated gene and expressing the condition. The FGFR3 gene is located on chromosome 4, and the mutation leads to the substitution of glycine with arginine at position 380 (G380R), disrupting normal bone growth and development.

**Why Each Wrong Option is Incorrect**
* **Option A:** Autosomal recessive. This mode of inheritance would require two copies of the mutated gene (one from each parent) to express the condition, which is not the case for achondroplasia.
* **Option B:** X-linked dominant. Achondroplasia is not linked to the X chromosome, and it does not exhibit the characteristic sex-linked patterns of inheritance.
* **Option C:** Mitochondrial inheritance. Achondroplasia is not related to mitochondrial DNA and does not exhibit the characteristic patterns of mitochondrial inheritance.

**Clinical Pearl / High-Yield Fact**
Achondroplasia is the most common form of short-limbed dwarfism, accounting for approximately 70% of all cases. It is essential to recognize the characteristic physical features and mode of inheritance to provide accurate genetic counseling to affected individuals and their families.

**Correct Answer:** C. Autosomal dominant.