The correct option is D All of the above
Meristematic cells are usually found at the apical portions of plants like the shoot apex and root apex, and are continuously dividing cells. They add to the primary or the vertical growth and secondary or horizontal growth of plants.
Meristematic cells have thin, less rigid cellulosic walls which are primary in nature, in that they are the first formed cell walls in actively dividing cells.
Meristematic cells have a dense protoplasm and large conspicuous nucleus. Plasmodesmatal connections occur abundantly in them. They have the ability to grow and divide.
These are small immature cells, isodiametric, rounded, oval or polygonal. There are no intercellular spaces. Vacuoles are absent or very small. Endoplasmic reticulum is small. Mitochondria have very simple structures and the rate of respiration is very high.