The correct option is B Companion cells
Gymnosperms are non-flowering, seed-bearing plants. Vascular bundles are present in the Gymnosperms but vessels are absent in the xylem and the phloem lacks the companion cells. The vessel element is typically found in the Angiosperms (flowering plants) and it is absent in the Gymnosperms as these plants do not produce flowers. The vessel element plays an important role in the flowering plants as they require more amount of water for their growth.