Gaurd cells is right answer that is option C .
Hope it helps.
Answer:
Cyanobacteria are microscopic organisms found in all kinds of water. They are single-celled organisms and produce their own food from sunlight via photosynthesis. Cyanobacteria are important to evolution because they developed the oxygen atmosphere we live in by producing waste from cyanobacteria. Plants also evolved from Cyanobacteria.
I believe the correct answer from the choices listed above is option D. <span>This is an example of cellular organization. Cells organize themselves according to their functions. Hope this answers the question. Have a nice day.</span>