What clade name is used for flowering plants?

The clade name used for flowering plants is Angiosperms.

Angiosperms are seed-producing vascular plants that make flowers and fruits. Their defining reproductive feature is that the ovules are enclosed within a carpel; after fertilization, surrounding tissues develop into a fruit that protects the seeds. Gymnosperms, by contrast, have exposed seeds.

The word comes from Greek angeion, meaning “container” or “vessel,” and sperma, meaning “seed.” The formal term Angiospermae was introduced in 1690, while its modern meaning developed through nineteenth-century botanical work. Modern classification systems generally treat angiosperms as an unranked clade.

Flowering plants are the most diverse major group of land plants, including grasses, orchids, oaks, roses, crops, and most broad-leaved trees. They rapidly diversified during the Cretaceous and now dominate many terrestrial ecosystems. The wrong options name other plant groups: bryophytes are mosses and relatives, pteridophytes include ferns, and gymnosperms include conifers.