question: Q:A genetic population study is being conducted to find the penetrance of a certain disease. This disease is associated with impaired iron metabolism and primarily affects the liver. Patients often present with diabetes and bronze skin pigmentation. After a genetic screening of 120 inhabitants with a family history of this disease, 40 were found to have the disease-producing genotype, but only 10 presented with symptoms. What are the chances of the screened patients with said genotype developing the disease phenotype?
   ? 
  {'A': '3%', 'B': '25%', 'C': '4%', 'D': '40%', 'E': '0.4%'},