In a study of a muscle disorder, several families exhibited vision problems, muscle weakness, and deafness. Analysis of the mtDNA (mitochondrial DNA) from affected persons in these families was analyzed using PCR (polymerase chain reaction) and gel electrophoresis. The unaffected samples were collected from multiple mitochondria, whereas each affected sample was collected from a single mitochondrion. What can you conclude about the affected individuals' mitochondrial DNA? A. There is no common deletion.
B. There is one common deletion.
C. There are two common deletions.
D. There are more than two common deletions.