Conservation of biodiversity is of two types, Ex Situ conservation and In Situ conservation
1. Ex Situ conservation means conservation outside the habitats by perpetuating sample population in genetic resource centres, for example, zoos, botanical gardens etc. or in the form of gene pools and gamete storage, germplasm banks for seeds, pollen etc.
2. In Situ conservation is the conservation of living resources through their maintenance within the natural ecosystems in which they occur. For example, national parks, sanctuaries, natural reserves, biosphere reserves, sacred grooves etc.
Hence, Seed Bank is an example of Ex Situ conservation.
So, the correct answer is 'Seed bank'.