Answer: Option B.
Gametophytes of seedless vascular plants.
Step-by-step explanation:
Gametophyte is an hapliod multicellular organism that develop from sporophyte generation. It is the sexual phase in plant life cycle.
Gametophyte seedless vascular plants lack do not produce seeds.
The gametophytes of seedless vascular plants have leaves. These leaves have chloroplast which capture sunlight energy with increased surface area. The light energy is converted to chemical energy in food and it fixed atmospheric carbon dioxide to carbohydrates.