HELP ASAP PLEASE! Phloem cells allow water to move up and down plants. How does a phloem cell's structure support its function? O A. Its end walls have openings that let water and nutrients pass through it. B. Its flexible shape allows it to control whether the stoma is open or closed. C. Its tiny holes allow water and oxygen to leave the plant. O D. Its shape increases a root's surface area for absorbing water and nutrients from the soil.