The correct option is A Thallophyta
∙ Thallophyta has the least tissue differentiation among all divisions of the kingdom Plantae. This group of plants do not have specific parts like roots, stem, leaves and flower. Algae belong to this group. They are aquatic plants and reproduce through spores.
∙ Bryophytes are photosynthetic, non-vascular terrestrial plants. Pteridophytes are vascular plants (with xylem and phloem) that produce spores.
∙ Gymnosperms are a group of vascular plants that do not produce fruits. Their seeds are naked.