Seed Plants Are Distinguished from Other Vascular Plants by

Seed plants are distinguished from other vascular plants by

A) the production of four megaspores, each of which develops into a female gametophyte.
B) an evolutionary trend to larger and more elaborate megagametophytes in the more advanced members of the group.
C) microgametophytes which are non-motile and dispersed by wind or animal vectors.
D) having a megagametophyte that is retained within the megasporangium, and is surrounded and protected by the integuments.
E) having different haploid and diploid phases of the life cycle.