An example of chemosynthetic bacteria is

Chemosynthetic bacteria include a group of autotrophic bacteria that use chemical energy to produce their own food. Like photosynthetic bacteria, chemosynthetic bacteria need a carbon source (e.g. carbon dioxide) as well as an energy source in order to manufacture their own food.

Examples of chemosynthetic bacteria are Sulphur bacteria and Nitrobacteria.

Chemosynthetic bacteria uses chemical energy to produce their own food such examples are Sulphur bacteria and Nitrobacteria. Hence, option D both B and C are correct.