Choose the word which is different from the rest.

The answer is B. Tree.

A trunk is the main stem of a tree. It supports the branches and leaves, and transports water and nutrients from the roots to the leaves.

A fruit is the seed-bearing structure that develops from the ovary of a flowering plant, after fertilization. Fruits are the means by which these plants disperse their seeds.

A leaf is an organ of a vascular plant, primarily of higher plants, that functions primarily in photosynthesis and gas exchange. Leaves are the primary organs of food production in most plants.

A flower is the reproductive structure found in flowering plants (angiosperms). Flowers are the means by which these plants sexually reproduce.