DoD rules apply to which type of animals?

The correct answer is that DoD rules apply to living and dead vertebrates used in research supported by the Department of Defense. This is due to the specific regulations set forth by the DoD that primarily focus on vertebrate animals because they are often the focus of biological research and experimentation.

Vertebrates include animals with backbones such as mammals, birds, reptiles, amphibians, and fish, and they are subject to a range of ethical and welfare considerations during research. Thus, the application of DoD rules is based on the recognition of the need for oversight in research involving these animals to ensure their humane treatment and to uphold scientific integrity.

In contrast, the other options are not aligned with DoD regulations. For example, while all mammals are indeed subject to various animal welfare laws, the DoD specifically doesn't apply to them without the context of their use in research. Marine mammals, while they are also vertebrates, do not represent the entire scope of the regulations. Lastly, the inclusion of invertebrates under DoD rules is outside the regulatory framework, as these animals are typically not covered by the same standards that apply to vertebrates.