32. A 23-year-old man comes to the physician because of a 1-month history of weakness and muscle pain after vigorous exercise. His mother, sister, and grandmother have a similar condition; however, his father's sister and her children are unaffected. A muscle biopsy specimen shows ragged red fibers. This condition most likely results from a mutation in a gene located in which of the following labeled structures in the photomicrograph? 00 O O A) B) E) B A E D C AR

32. A 23-year-old man comes to the physician because of a 1-month history of weakness and muscle pain after vigorous exercise. His mother, sister, and grandmother have a similar condition; however, his father's sister and her children are unaffected. A muscle biopsy specimen shows ragged red fibers. This condition most likely results from a mutation in a gene located in which of the following labeled structures in the photomicrograph? 00 O O A) B) E) B A E D C AR