Which part of the flower is a tube that leads to the ovary?

The style is the correct answer because it is the slender structure that connects the stigma, where pollen is deposited, to the ovary, which contains the ovules. The style acts as a tube or conduit, allowing pollen tubes to grow down from the stigma through the style and reach the ovary for fertilization. This process is crucial for sexual reproduction in flowering plants, as it facilitates the transfer of male gametes to female ovules.

In contrast, the filament is a part of the stamen that supports the anther and does not play a role in connecting to the ovary. The receptacle serves as the thickened part of the stem from which the flower parts develop, providing structural support but not connecting to the ovary directly. The pedicel is the stalk that supports the flower itself, similar to the way that a stem supports leaves. Each of these structures serves important functions in the overall reproductive process of plants, but the style is specifically designed to lead to the ovary.