It has warmed roughly 1.33°F.
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).
Because these smaller cells can access and pass through the membranes of the other cell membranes and permeable coverings easily and voluntarily unlike larger cells. It is also for efficient for these smaller and miniscule cells to penetrate and travel, delivering and transporting goods and materials such as nutrients, oxygen and waste throughout the body without consuming enough energy and conserving lesser space.
For simple reasons, they are faster, more efficient and consumes little space, and most especially depletes lesser energy.