Which of the following is true according to the text？A．Ashanthi needs to receive gene-ther

Which of the following is true according to the text？

A．Ashanthi needs to receive gene-therapy treatment constantly.

B．Despite the huge funding, gene researches have shown few promises.

C．Therapeutic genes are carried by harmless viruses.

D．Gene-doping is encouraged by world agencies to help athletes get better scores.