How does a bee pollinate a flower?

A bee pollinates a flower by engaging in a two-step process that involves both collecting nectar and pollen. When a bee visits a flower in search of nectar, it inadvertently brushes against the flower's anthers, which are the parts of the flower that produce pollen. This pollen adheres to the bee's body due to its fuzzy hair and sticky surfaces.

As the bee moves from flower to flower, it transfers some of this pollen to the stigma of other flowers, facilitating cross-pollination. This action is critical for many plants, leading to fertilization, seed production, and genetic diversity. Thus, the correct answer highlights not just the gathering of nectar, but also the crucial role of the bee in transferring pollen between flowers, which is essential for the reproductive success of many flowering plants.

The other options do not encompass this dual role that bees play in pollination, which is a critical interaction between the insects and flowering plants.