The correct option is
C Monocot root
In monocot root, vascular bundles are radial in arrangement. There are eight bundles each of xylem and phloem. Hence, the condition is described as polyarch.
Xylem is described as exarch. In dicot root, vascular bundles are described as radial and tetrarch. There are four bundles each of xylem and phloem occurring alternately. Xylem is described as exarch.
In dicot stem, vascular bundles are eight in number, arranged in form of a broken ring. The vascular bundles are conjoint, collateral and open. Xylem is on the inner surface and phloem on the outer surface. Xylem is described as endarch.
In monocot stem, xylem is described as endarch. Presence of numerous vascular bundles irregularly scattered with centrifugal arrangement. Vascular bundles are conjoint, collateral and closed with endarch xylem. Thus, option C is correct.