Root hairs maximize absorption efficiency

Steps:

• Identify root hairs as extensions of root epidermal cells that increase surface area.
• Recall that plants absorb water and minerals primarily through roots via osmosis and diffusion.
• Link large surface area to faster uptake rates, essential for plant survival.
• Eliminate options unrelated to absorption functions.

Why D is correct:

• Root hairs' large surface area facilitates greater diffusion and osmosis of water and mineral ions from soil, per Fick's law of diffusion, which states rate increases with surface area.

Why the others are wrong:

• A: Anchoring is a root function, but surface area specifically aids absorption, not structural support.
• B: Starch storage occurs in roots or tubers, unrelated to root hair surface area.
• C: Sugar transport happens via phloem after photosynthesis, not root hair absorption.

Final answer: D