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.

Transgenic animals can be specifically designed to allow the study of  how genes are regulated, and how they affect the normal functions of the body and its development. Transgenic animals help in understanding of how genes contribute to the development of disease. These animals also produce useful biological products. They help in vaccine safety testing before they are used on humans.