Pteridophytes and gymnosperm have vascular tissues. Gymnosperm bear seeds but pteridophytes do not bear seeds. Algae and bryophyte do not posses vascular tissues.
Therefore the answer is pteridophytes.

The correct answer is option 'C' - Pteridophytes.

Pteridophytes are a group of plants that have vascular tissue but do not produce seeds. They are commonly known as ferns and include plants like ferns, horsetails, and clubmosses. Let's dive into the details to understand why pteridophytes are the correct answer.

1. Introduction to vascular tissue:
- Vascular tissue is a specialized tissue found in plants that is responsible for the transport of water, minerals, and nutrients throughout the plant.
- It consists of two types of tissues: xylem and phloem.
- Xylem transports water and minerals from the roots to the other parts of the plant.
- Phloem transports sugars, hormones, and other organic molecules to various parts of the plant.

2. Plants lacking seeds:
- Seedless plants reproduce through spores instead of seeds.
- Spores are single-celled reproductive structures that can develop into new individuals under favorable conditions.

3. Algae:
- Algae are a diverse group of plants that range from single-celled organisms to large, multicellular seaweeds.
- While some types of algae have vascular tissue, they also have other reproductive structures such as gametes or spores, which means they are not entirely lacking seeds.
- Therefore, algae cannot be considered as plants lacking seeds.

4. Bryophytes:
- Bryophytes include mosses, liverworts, and hornworts.
- They are non-vascular plants, meaning they do not possess specialized vascular tissues like xylem and phloem.
- However, bryophytes reproduce through spores and have other reproductive structures, such as gametophytes and sporophytes.
- Hence, bryophytes also do not fit the category of plants lacking seeds.

5. Gymnosperms:
- Gymnosperms are a group of seed-producing plants that include conifers, cycads, and ginkgoes.
- They have well-developed vascular tissue and produce seeds.
- Gymnosperms are characterized by their "naked" seeds, which are not enclosed within fruits.
- Therefore, gymnosperms cannot be considered as plants lacking seeds.

6. Pteridophytes:
- Pteridophytes, represented by ferns, horsetails, and clubmosses, have vascular tissue but do not produce seeds.
- They reproduce through spores, which are produced in specialized structures called sporangia.
- The spores give rise to gametophytes, which produce gametes for sexual reproduction.
- This life cycle, known as alternation of generations, is characteristic of pteridophytes.
- Thus, pteridophytes are the only option among the given choices that represent plants with vascular tissue lacking seeds.

In conclusion, pteridophytes are the correct answer as they possess vascular tissue but do not produce seeds. They reproduce through spores instead.