**Core Concept**
Autosomal dominant disorders are characterized by the presence of a single copy of a mutated gene, leading to the expression of the disease. This type of inheritance pattern means that each child of an affected parent has a 50% chance of inheriting the mutated gene and the disease.

**Why the Correct Answer is Right**
Autosomal dominant disorders often result from mutations in genes involved in critical cellular processes. For example, Huntington's disease is caused by an expansion of a CAG repeat in the Huntingtin gene, leading to toxic protein accumulation and neuronal degeneration. The presence of a single mutated allele is sufficient to cause the disease, as the normal allele is not able to compensate for the loss of function.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it would imply a recessive pattern of inheritance, where two copies of the mutated gene are required to express the disease.
**Option B:** This option is incorrect as it would imply an X-linked pattern of inheritance, where the mutated gene is located on the X chromosome and affects males more frequently than females.
**Option C:** This option is incorrect as it would imply a mitochondrial pattern of inheritance, where the mutated gene is located in the mitochondria and affects tissues with high energy demands, such as the brain and muscles.

**Clinical Pearl / High-Yield Fact**
A key feature of autosomal dominant disorders is the phenomenon of germline mosaicism, where the mutated gene is present in a proportion of the parent's germ cells, leading to a higher risk of recurrence in subsequent offspring.

**Correct Answer: D.**