**Core Concept**
Achondroplasia is a genetic disorder that affects bone growth and development, characterized by short stature and characteristic skeletal features. It is caused by mutations in the FGFR3 gene, which plays a crucial role in regulating bone growth.

**Why the Correct Answer is Right**
Achondroplasia is an autosomal dominant disorder, meaning that only one copy of the mutated gene is needed to express the condition. When a parent with achondroplasia has a child, there is a 50% chance that the child will inherit the mutated gene and develop the condition. This is because the mutated gene is located on an autosome (a non-sex chromosome), and each parent contributes one copy of the gene to their offspring.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because achondroplasia is not an autosomal recessive disorder, which would require two copies of the mutated gene (one from each parent) to express the condition.
* **Option B:** This option is incorrect because achondroplasia is not an X-linked disorder, which would be inherited in a pattern linked to the X chromosome (females would be more commonly affected).
* **Option C:** This option is incorrect because achondroplasia is not a mitochondrial disorder, which would be inherited from the mother and affect tissues that use mitochondrial DNA.
* **Option D:** This option is incorrect because achondroplasia is not a multifactorial disorder, which would involve the interaction of multiple genetic and environmental factors.

**Clinical Pearl / High-Yield Fact**
Achondroplasia is the most common cause of short-limbed dwarfism, and it is essential to diagnose and manage the condition to prevent complications such as hydrocephalus, spinal stenosis, and sleep apnea.

**Correct Answer:** A. Autosomal dominant