Which statement best explains heteroplasmy in mitochondrial inheritance?

Which statement best explains heteroplasmy in mitochondrial inheritance?

• A. A mixture of wild-type and mutant mtDNA within a cell leads to variable disease severity depending on the proportion of mutant genomes.
• B. All mitochondria carry the same genome, leading to uniform expression.
• C. Heteroplasmy only occurs when paternal mtDNA is transmitted.
• D. Heteroplasmy results in complete absence of phenotype.

Answer: (A)