The correct option is A Medullary rays
In dicot stems, the cells of the medullary rays develops into interfascicular cambium.
Interfascicular cambium along with the intrafascicular cambium present between primary xylem and primary phloem forms a continuous ring of vascular cambium.
Xylem parenchyma are thin-walled living cells that store food materials in the form of starch or fat and conduct water radially.
Endodermis is a layer of cells in the cortex of root and some stems, surrounding a vascular bundle.
Pericycle is a thin layer of plant tissue between the endodermis and the phloem.