The structure of a root hair cell support its function as it sticks out from the cell into the soil. Hence the correct option is a.
The structure of a root hair is specifically adapted to support its essential function of nutrient absorption from the soil. Root hairs are thin, elongated extensions that protrude from the surface of plant root cells. This structural feature significantly increases the surface area available for nutrient absorption.
By sticking out into the soil, root hairs create a larger interface for the exchange of water and minerals with the surrounding soil particles. This increased surface area enhances the plant's ability to absorb essential nutrients, such as water and minerals, vital for its growth and metabolic processes. The microscopic nature of root hairs allows them to navigate through the soil particles, facilitating efficient nutrient uptake and contributing to the overall health and development of the plant. Hence the correct option is a.