Which of the following is a characteristic of root hairs?

Root hairs are indeed primarily known for their role in assisting with nutrient absorption from the soil. They are tiny, hair-like structures that extend from the root epidermis and significantly increase the surface area of the root system. This increased surface area allows for a greater interaction with soil particles and enhances the plant's ability to take up water and dissolved nutrients, facilitating efficient nutrient and moisture absorption.

The other choices, while relevant to plant structures in general, do not accurately describe root hairs. For example, root hairs do not have a thick cuticle; in fact, they typically lack a cuticle altogether to maximize absorption. They also do not perform photosynthesis since this process primarily occurs in the leaves where chlorophyll is present. Lastly, while some parts of plants do serve storage functions (like roots or stems), root hairs are specifically adapted for absorption and not for storage.