Photosynthesis
Photosynthetic bacteria use the energy of the sun to make their own food. In the presence of sunlight, carbon dioxide and water are turned into glucose and oxygen. The glucose is then turned into usable energy. Glucose is like the "food" for the bacteria. An example of photosynthetic bacteria is cyanobacteria, as seen in the opening image. These bacteria are sometimes called blue-green algae, although they are not algae, due to their numerous chlorophyll molecules.
Decomposers
Bacteria known as decomposers break down wastes and dead organisms into smaller molecules. These bacteria use the organic substrates they break down to get their energy, carbon, and nutrients they need for survival.
Chemotrophs
Bacteria can also be chemotrophs. Chemosynthetic bacteria, or chemotrophs, obtain energy by breaking down chemical compounds in their environment. An example of one of these chemicals broken down by bacteria is nitrogen-containing ammonia. These bacteria are important because they help cycle nitrogen through the environment for other living things to use. Nitrogen cannot be made by living organisms, so it must be continually recycled. Organisms need nitrogen to make organic compounds, such as DNA
Where i got the information https://www.ck12.org/biology/bacteria-nutrition/lesson/Bacteria-Nutrition-MS-LS/
3. Producers are photosynthesizing organisms, so basically any kind of plant. Consumers are anything that eat anything else.
4.Herbivores only eat plants
5. Omnivores eat both plants and other animals
6. Carnivores only eat animals
7. Notice how many things eat the krill. If there was a very small krill population, there wouldn't be nearly enough krill for everything to eat, so the population of everything else would be reduced as well.
The answer to the question is B.