What defines angiosperms amongst plant groups?

Angiosperms are defined by their production of seeds that are enclosed within an ovary, which typically develops into a fruit. This characteristic distinctly sets them apart from other plant groups, such as gymnosperms, which produce seeds that are not enclosed in an ovary but are often found on cones. The evolutionary advantages of having seeds enclosed in fruits include greater protection for the developing seeds and enhanced dispersal mechanisms, as animals may aid in the distribution of seeds contained within the fruit.

The other options highlight characteristics of different plant groups or define characteristics that are not applicable to angiosperms. For example, reproduction through spores is typical of non-flowering plants like ferns and mosses. The absence of vascular tissues is a characteristic of non-vascular plants like bryophytes. Lastly, the presence of cones is a feature associated with gymnosperms, which do not produce flowers.