Answer the following question given this paragraph: 

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.


Q: Bacteria can be chemotrophs, which obtain what by breaking down chemical compounds in their environment?

 Choices:

- waste

- chemials

- food

- energy

A:
energy
