Non vascular embryophyta refers to the group of plants that lack vascular tissues and reproduce through spores. This group includes bryophytes, which are the only correct option given in the question. Let us understand this in detail.

Bryophytes
Bryophytes are non-vascular plants that include mosses, liverworts, and hornworts. They have a simple body structure, lacking true roots, stems, and leaves. Instead, they have rhizoids, which anchor the plant to the ground and absorb water and nutrients. Bryophytes reproduce through spores, which are produced in capsules called sporangia.

Thallophyta and Pteridophyta
Thallophyta refers to a group of plants that lack distinct stem, roots, and leaves. They include algae, fungi, and lichens. Pteridophyta, on the other hand, are vascular plants that include ferns, horsetails, and clubmosses. They have true roots, stems, and leaves, and reproduce through spores.

Conclusion
In conclusion, non vascular embryophyta refers to bryophytes, which are the only correct option given in the question. Thallophyta and Pteridophyta are not non vascular embryophyta as they either lack true roots, stems, and leaves (Thallophyta) or have vascular tissues (Pteridophyta).