Step 1: Understand the term 'gymnosperms'. Gymnosperms are a group of seed-producing plants that do not form flowers or fruits. Their seeds are exposed, often in cones, unlike angiosperms whose seeds are enclosed within fruits.
Step 2: Review the four groups of living gymnosperms. These groups are Cycads, Ginkgo, Conifers, and Gnetophytes. Each group represents a distinct lineage within gymnosperms.
Step 3: Compare the options provided in the question. Eliminate groups that are not gymnosperms. For example, Angiosperms, Bryophytes, Lycophytes, and Pteridophytes are not gymnosperms; they belong to other plant categories.
Step 4: Further eliminate groups that consist of non-seed plants. Ferns, Mosses, Liverworts, and Hornworts are non-seed plants and belong to different classifications such as bryophytes and pteridophytes.
Step 5: Confirm the correct answer. Cycads, Ginkgo, Conifers, and Gnetophytes are the four groups of living gymnosperms, as they are seed-producing plants without flowers or fruits.