What field of science is primarily concerned with the study of life?

The field of science primarily concerned with the study of life is biology. Biology encompasses the exploration of living organisms, including their structure, function, growth, evolution, distribution, and interactions with their environments. It is a vast field that covers various sub-disciplines, such as microbiology, zoology, botany, and ecology, each focusing on different aspects of life and living systems.

While physics deals with the fundamental principles of matter and energy, and chemistry focuses on the composition, structure, and properties of substances, neither of these fields is dedicated specifically to the study of living organisms. Astronomy, on the other hand, involves the study of celestial bodies and the universe beyond Earth, making it quite distinct from biological sciences. Hence, biology is the correct choice as it directly addresses the complexities and diversity of life on our planet.