Choose the common feature among Bryophytes, Pteridophytes and Gymnosperms.

In all bryophytes, pteridophytes and gymnosperms meiosis takes place in spore mother cells during sporogenesis. Female gametophyte is retained always in the sporophyte or ovule of sporophyte in gymnosperms. In heterosporous pteridophytes, the female gametophyte is retained in the megasporangium for variable periods. In Bryophytes the gametophytes are independent. The male gametophytes of gymnosperms are few celled. The female gametophyte of gymnosperms, gametophytes of both pteridophytes and bryophytes are multicellular. Flagellated male gametes are seen in bryophytes and pteridophytes and very rarely in some gymnosperms like Cycas.