Which treatment would be considered gene therapy? removing an organ that is not working properly

giving medicine to match the effects of a gene
working correctly

introducing a new gene to the body

giving medicine to kill infections

introducing a new gene to the body

Explanation:

This because gene therapy is the process where gene from genetic material or DNA is transfered or introduce into the body of a patient to treat diseases or certain infections. This is done to cure ailments. This is a process that modify the gene that is present in the patient body which is the source or cause of the disease and then make it to work normally.

"do a testcross with a homozygous recessive plant."