Root hair cells' elongated shape boosts absorption

Steps:

• Identify the cell: root hair cells in plant roots have tubular extensions.
• Analyze shape benefit: elongation maximizes surface area without adding volume.
• Link to function: larger area facilitates diffusion of water and nutrients from soil.
• Match to options: broadest accurate description is general uptake enhancement.

Why D is correct:

• Root hairs' shape increases surface area, enhancing passive uptake of water and ions via diffusion, as per Fick's law of diffusion.

Why the others are wrong:

• A: Shape aids absorption, not active searching for ions.
• B: Incomplete phrasing; lacks clear benefit explanation.
• C: Limits to water only, ignoring ions and nutrients.

Final answer: D