Correct Answer - D
Vascular bundles which contains both xylem and phloem are called conjoint vascular bundles contain both xylem, phloem and a strip of vascular cambium (between phloem and xylem of each vascular bundle) called intrafascicular (or fascicular) cambium. It produces secondary tissues. such vascular bundles are discribed as open because the original or primary phloem and xylem separate on the production of secondary tissues by vascular cambium. thus conjoint and open vascular bundles will be observe in dicot stem.
