The correct answer is option 'C' - Ciliated sperms.

Bryophytes are a group of non-vascular plants that includes mosses, liverworts, and hornworts. They are considered to be the earliest land plants and have an aquatic ancestry. This means that their ancestors were aquatic organisms that eventually evolved to live on land.

One of the key features that shows the aquatic ancestry of bryophytes is the presence of ciliated sperms. Let's explore this in more detail:

**Ciliated sperms in bryophytes:**
1. In bryophytes, the male reproductive organs, called antheridia, produce sperm cells.
2. These sperm cells are flagellated, meaning they have one or more whip-like appendages called flagella that enable them to move.
3. The flagella help the sperm to swim through water and reach the female reproductive organs, called archegonia, where fertilization takes place.
4. The presence of flagella and the ability to swim in water are adaptations that are commonly found in aquatic organisms.
5. This indicates that the ancestors of bryophytes were likely aquatic organisms that relied on water for reproduction.

**Other features of bryophytes:**
1. Apart from ciliated sperms, there are other features that also indicate the aquatic ancestry of bryophytes.
2. These include their simple structure, lack of vascular tissues, and dependence on water for various life processes.
3. Bryophytes have a dominant gametophytic plant body, which means that the haploid gametophyte generation is more prominent and independent compared to the diploid sporophyte generation.
4. This dominance of the gametophyte is a characteristic trait of ancestral aquatic plants.
5. The sporophyte generation in bryophytes is attached to and depends on the gametophyte for nutrition and support.
6. Bryophytes also have biflagellate spores, which means that their spores have two flagella that aid in dispersal through water.

In conclusion, the presence of ciliated sperms in bryophytes is a characteristic feature that indicates their aquatic ancestry. The ability of these sperms to swim through water and reach the female reproductive organs suggests that the ancestors of bryophytes were likely aquatic organisms that evolved to live on land.

Ciliated sperms shows that in earlier times that need water for fertilization and male gamete moves by cilia in the water for fertilization.