Answer:
The correct answer will be option-C
Step-by-step explanation:
The cell theory which suggested that cell is the functional and structural unit of life and all living organism are made of cells.
This theory was proposed in 1839 after the two professionals Theodor Schwann (zoologist) and Matthias Schleiden (botanist) met in a meeting. They both independently discovered that animals and plants are made up of similar appearing structures.
They together demonstrated that both animals and plants are made up of similar structures called cells and gave rise to the cell theory.
Thus, option-c is the correct answer.