Which of the Following Is True of Seedless Vascular Plants

Which of the following is true of seedless vascular plants?

A) Extant seedless vascular plants are larger than the extinct varieties.
B) Whole forests were dominated by large, seedless vascular plants during the Carboniferous period.
C) They produce many spores, which are really the same as seeds.
D) The gametophyte is the dominant generation.
E) Sphagnum is an economically and ecologically important example.