Bentham and Hooker's classification system was primarily for which type of plants?

Correct answer: Seed plants (Spermatophyta)

Direct answer: B, seed plants or Spermatophyta. Bentham and Hooker proposed a natural system of classification mainly for seed-bearing plants. Their treatment was especially detailed for flowering plants, or angiosperms, which they arranged into dicotyledons and monocotyledons; gymnosperms were also recognized as a separate group within the seed plants. A is incomplete because gymnosperms are only one part of Spermatophyta. C, algae, and D, bryophytes, are non-seed plant groups and were not the principal focus of this system. The word “primarily” is important: the system is remembered for its extensive treatment of seed plants, especially angiosperms, rather than for classifying every plant group equally. Memory cue: Bentham–Hooker means a natural classification of seed plants, with detailed angiosperm grouping.