Which Statement Comparing Ex Vivo and in Vivo Gene Therapies

Which statement comparing ex vivo and in vivo gene therapies is true?

A) Ex vivo therapy involves the germ line, whereas in vivo therapy involves somatic cells.
B) In ex vivo therapy cells are removed from the body, whereas in in vivo therapy the gene is inserted directly into the patient.
C) Viruses are used to get the gene into the host cell in ex vivo therapy.
D) Only ex vivo therapy is considered ethical.
E) In vivo therapy is performed before birth and ex vivo therapy is performed after birth.