**Core Concept**
Mendelian inheritance refers to the transmission of genetic traits from one generation to the next according to the laws proposed by Gregor Mendel. This form of inheritance is categorized into several patterns, including autosomal dominant, autosomal recessive, X-linked dominant, X-linked recessive, and Y-linked.

**Why the Correct Answer is Right**
The correct answer is related to the prevalence of autosomal dominant disorders. This is because many autosomal dominant conditions are caused by mutations in a single allele, and these mutations are more likely to be expressed due to the presence of only one normal allele. Examples of autosomal dominant disorders include neurofibromatosis type 1, achondroplasia, and Marfan syndrome.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because autosomal recessive disorders are less common than autosomal dominant disorders. Autosomal recessive conditions require mutations in both alleles to manifest symptoms.
* **Option B:** This option is incorrect because X-linked dominant disorders are relatively rare and often manifest in both males and females. Examples include Rett syndrome and Aicardi syndrome.
* **Option C:** This option is incorrect because Y-linked disorders are extremely rare and usually affect males only. An example is the Y-linked color vision deficiency.

**Clinical Pearl / High-Yield Fact**
Mendelian disorders often have a high degree of penetrance, meaning that individuals with a specific genotype are likely to express the associated phenotype.

**Correct Answer: A. Autosomal dominant disorders are the most common among diseases with Mendelian inheritance.**