Why the vascular strands (xylem and phloem) show radial arrangement in roots?

Explanation

The vascular tissues (xylem an.d phloem strands) are so arranged in roots that no phloem lies exterior to xylem strands. This arrangement is helpful in maintaining the inward movement of water from the epidernus to enter the xylem without crossing the phloem strand, where a separate kind of conduction is taking place