The most advanced spermatophyte that forms the largest group of plant kingdom is the

Spermatophytes are seed-bearing plants. They are divided into two major groups: gymnosperms (seeds not enclosed in a fruit) and angiosperms (seeds enclosed within a fruit, formed from the ovary wall).

Angiosperms are considered the most advanced spermatophytes because they possess several evolutionary innovations:

• Double fertilisation, which produces both an embryo and a nutrient-rich endosperm.
• Flowers, which allow efficient pollination by wind, water, insects, and other animals.
• Fruits, which aid in seed dispersal.
• Highly efficient vascular tissue, including vessel elements in the xylem.

Angiosperms also form the largest group in the plant kingdom, with over 300,000 known species, far exceeding the roughly 1,000 species of gymnosperms.

Ferns are not spermatophytes at all; they reproduce by spores, not seeds. Cones are reproductive structures of gymnosperms, not a plant group. Gymnosperms are spermatophytes but are less advanced and far fewer in number than angiosperms.

The correct answer is therefore angiosperm.