The cell theory is a well-tested explanation of observations that was formed from the contributions of several different scientists. Option 3 is correct.
This is the reason why:
A great deal of observation and testing form the basis of the cell theory. Researchers such as Schleiden, Schwann, and Virchow made significant contributions based on their microscopic observations of many creatures. It was neither an individual's theory nor a haphazard estimate.
If the theory was based on speculative theories or incomplete observations, it would not be able to account for all known living organisms.
Despite the diversity of cells, the theory's fundamental ideas hold true for all cell types. This demonstrates how well the theory explains the underlying ideas of life.
The complete option are :
Which of the following best explains how the cell theory was developed?
Cells are so diverse that scientists had to come up with an explanation that would apply to all types of cells.
Mutations occur and cause changes in cells so scientists could not develop a law that would apply to all forms of cells.
The cell theory is a well-tested explanation of observations that was formed from the contributions of several different scientists.
The cell theory was developed through extensive library research because it would be impossible to test all living things for the presence of cells.