Ex situ conservation of germplasm in Botanical Gardens:

Botanical gardens are living museums that house various plant species from different parts of the world. They play a crucial role in plant conservation, education, and research. One of the primary purposes of botanical gardens is the ex situ conservation of germplasm. Ex situ conservation refers to the preservation of plant species outside their natural habitat, such as in botanical gardens, seed banks, or other facilities.

The following are some of the reasons why botanical gardens serve as ex situ conservation sites:

1. Preservation of plant diversity: Botanical gardens preserve plant diversity by maintaining living collections of rare, threatened, and endangered plant species. These collections can also serve as a backup for wild populations in case of natural disasters or other threats.

2. Scientific research: Botanical gardens support scientific research on plant taxonomy, genetics, ecology, and evolution. Researchers can study the plants in botanical gardens to understand their biology, behavior, and interactions with other organisms.

3. Education: Botanical gardens provide an excellent opportunity for the public to learn about plant diversity, ecology, and conservation. Visitors can see different plant species, learn about their uses, and understand the importance of preserving them.

4. Seed banks: Botanical gardens often have seed banks that store seeds of various plant species. These seeds can be used for research, conservation, or restoration purposes.

In conclusion, botanical gardens serve as ex situ conservation sites by preserving plant diversity, supporting scientific research, educating the public, and maintaining seed banks. Therefore, option 'C' is the correct answer.