Answer:
They speed up chemical reactions. Without them you wouldn't be alive. They break down macromolecules, and also lower the amount of energy needed for a chemical reaction to happen.
The correct answer is: first level.
Maslow's hierarchy of needs is a theory in psychology that is represented by hierarchical levels of human needs within a pyramid. There are five levels of needs:
1. Physiological (food, water, rest..),
2. Safety ,
3. love and belonging (friends, intimated relationships),
4. esteem (feeling of accomplishment),
5. self-actualization (achieving your own potentials).
