What are the identifying features of meristematic tissues? (a) thick cellulose wall, small vacuoles, dense cytoplasm, small nuclei (b) thin cellulose wall, almost no vacuoles, dense cytoplasm, prominent nuclei (c) thin cellulose wall,no vacuoles, sparse cytoplasm, prominent nuclei (d) thick cellulose, large vacuoles, sparse cytoplasm, small nuclei