The correct answer is c. sporophyte.
The given picture is of fern leaves. Ferns are first true land plants. The leaves are the part of sporophyte. On the underside of fern leaves develop sporangia. Within sporangia, spores are formed after meiosis. Spores are the first cell of the gametophyte, later spores germinate to form gametophyte whose cells are haploid. On gametophyte sex organs develop which produce gametes. Gametes on fusion zygote. Thus, zygote is first cell of sporophyte. Thus in the life cycle of fern sporophyte alternates with gametophyte.
