What does the ovary of a flower mature into?

The ovary of a flower matures into fruit as part of the reproductive cycle of flowering plants. After fertilization occurs, the ovule within the ovary develops into seeds, while the surrounding tissues of the ovary itself grow and transform into the fruit. The fruit serves several critical functions: it protects the developing seeds, aids in their dispersal by attracting animals that consume the fruit and later excrete the seeds elsewhere, and may also provide nourishment for the seeds as they develop.

In contrast, the other choices do not align with botanical processes. Leaves are primarily involved in photosynthesis and do not arise from the ovary, while stems provide structural support and transport water and nutrients, also not originating from the ovary. Seeds result from the ovary but do not constitute the mature form of the ovary itself.