**Core Concept**
Mitochondrial inheritance refers to the pattern of inheritance of mitochondrial DNA (mtDNA), which is passed down from mother to offspring. Mitochondria are the energy-producing structures within cells, and their DNA is responsible for encoding genes involved in energy production.

**Why the Correct Answer is Right**
Mitochondrial DNA is inherited solely from the mother, as only egg cells contribute mitochondria to the fertilized egg. Since mitochondrial DNA is not recombined like nuclear DNA, affected females can pass their mitochondrial mutations to all of their offspring, regardless of their father's genetic makeup. This is because the mitochondria in a fertilized egg are derived solely from the egg's mitochondria. Therefore, an offspring born to an affected female will indeed be affected.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is incorrect because an affected male cannot pass on his mitochondrial mutations to his offspring, as his sperm do not contribute mitochondria to the fertilized egg.

**Option C:** This statement is incorrect because an affected female can pass on her mitochondrial mutations to her offspring, making them affected as well.

**Option D:** This statement is incorrect because only option B is true; the other options are false.

**Clinical Pearl / High-Yield Fact**
Mitochondrial diseases are a group of disorders caused by mutations in mitochondrial DNA, and they can affect multiple systems of the body, including the nervous, muscular, and cardiovascular systems. Some common examples of mitochondrial diseases include Kearns-Sayre syndrome, MELAS syndrome, and Leber's hereditary optic neuropathy.

**✓ Correct Answer: B. An offspring born to an affected female will be affected**