The correct option is D Riccia
All plants and some algae species show alternation of generations is their life cycle. The sporophyte is the diploid generation and the gametophyte is the haploid generation. In Bryophytes which are the nonvascular plants, the dominant phase is gametophyte. Riccia is a liverwort belonging to Bryophyta and hence shows a dominant gametophytic stage. Thus the correct answer is option D.