Answer the following question given this paragraph: 

Each field of life science has its own specific body of knowledge and relevant theories. However, two theories are basic to all of the life sciences. They form the foundation of every life science field. They are the cell theory and the theory of evolution by natural selection. Both theories have been tested repeatedly. Both are supported by a great deal of evidence.


Q: The cell theory and the theory of evolution by natural selection are basic to all fields in what branch of science?

 Choices:

- rock science

- zoology

- chemistry

- life science

A:
life science
