Choose the reasons why transgenic animals are designed and mark the correct option.

a. To understand of how genes contribute to disease.

b. To produce useful biological products.

c. To test the safety of vaccines.

d. To study of how genes are regulated.

e. To study how genes affect the normal functions of the body.

• A

  a, b and c

• B

  b and c

• C

  a, d and e

• D

  a, b, c, d and e