## Core Concept
The question tests understanding of genetic disorders and their inheritance patterns. Mendelian inheritance refers to the pattern of inheritance seen for single gene disorders, which follow the laws of Mendel. However, not all single gene disorders follow a straightforward Mendelian pattern due to various genetic mechanisms.

## Why the Correct Answer is Right
The correct answer, **C. Mitochondrial inheritance**, is a type of single gene disorder that does not follow Mendelian inheritance patterns. This is because mitochondrial DNA is inherited solely from the mother and does not follow the typical autosomal dominant or recessive patterns described by Mendel. Mitochondrial inheritance is characterized by the transmission of disease-causing mutations in the mitochondrial DNA from mother to all offspring.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is blank and cannot be evaluated.
- **Option B:** This option is blank and cannot be evaluated.
- **Option D:** This option is blank and cannot be evaluated.

## Clinical Pearl / High-Yield Fact
A key point to remember is that **mitochondrial disorders** often present with a mix of symptoms affecting multiple organ systems, and their inheritance pattern can provide a critical clue to diagnosis. Since only egg cells contribute mitochondria to the zygote, these disorders are maternally inherited.

## Correct Answer: C. Mitochondrial inheritance.