Which of the Following Health Disorders Can Be Treated with Ex

Which of the following health disorders can be treated with ex vivo gene therapy?

A) Liver cells lack a protein that enables it to remove cholesterol from the blood which leads to high levels of cholesterol in the blood. This can increase the patients susceptibility to heart attacks.
B) The liver cells lack a protein that causes it to produce excessive cholesterol which leads to high levels of cholesterol in the blood. This can increase the patients susceptibility to heart attacks.
C) A gene is implanted that will code for the correct transmembrane carrier of the chloride ion.
D) Genes are implanted that make healthy cells more tolerant to chemotherapy while making the tumor cells more susceptible to chemotherapy.