Which of the Following Is a Possible Use for Gene

Which of the following is a possible use for gene cloning?

A) Cloned genes can be introduced into bacteria or livestock to make pharmaceutical products such as insulin.
B) Cloned genes can be introduced into plants and animals to alter their traits.
C) Cloned genes can be used to treat diseases.
D) Large amounts of protein can be produced to study structure and function.
E) All of the choices are correct.