Answer:
3. Anatomy.
Explanation:
Anatomy is a branch of science which studies the physical structure of humans, animals, and other living beings. Anatomy is a part of biological studies. This field in the science is focussed on the shape, structure, and the relationship relevant to the living organisms.
Anatomy is further divided into two branches, namely, microscopic anatomy and macroscopic anatomy.
Therefore, the correct answer is option 3.
NaOH is not a compound because it contains three instead of two.
