Statement A: Secondary medullary rays may be formed from cells of primary medullary rays of dicot stem upon dedifferentiation and later redifferentiation.

Statement B: Cells of primary medullary rays present between fascicular cambia of adjacent vascular bundles of dicot stem regain meristematic activity and form interfascicular cambium which give rise ray parenchyma of secondary xylem and secondary phloem that together form vascular rays or secondary medullary rays.