Seedless vascular plants are:
Ferns
The correct option is C:
Explanation of the correct option:
Vascular plants
Seedless vascular plants
Explanation of the incorrect option:
Option A:
Liverworts belong to the phylum Bryophyta and are avascular.
Option B:
Mosses also belong to the phylum Bryophyta and are avascular.
Option D:
Cycads belong to the division Gymnospermae which consists of seed-producing plants.
Final answer: The seedless vascular plants are ferns.