Hello!
Cell theory was developed as a result of many scientists' work.
Some of these people are Matthias Schleiden, Theodor Schwann, and Rudolf Virchow. They found out that all plants are made of cells, all animals are made of cells, and all cells are made from the division of other cells (respectively).
On the other hand, Robert Hooke studied cork tissue under the microscope, and he was the one who discovered the cell. Anton van Leeuwenhoek was the first to observe living things using a microscope.
Hope this helps!
Answer:
B) Observations and conclusions of many scientists
