I believe that the answer is A, if I am not mistaken!
Your blood would not be oxygenated so cells and tissues and muscles wouldn't receive any oxygen
The answer is; D.
This can be called a secondary ecological succession because it includes the disruption of the former ecology, rather than the ecological succession from a new environment-primary succession. The invasive species outcompete the native species in their environment. In addition, the invasive species lack a natural predator hence spread unregulated in the environment.
Answer - Theory
Reasoning - Your best bet and term to describe the evolution by natural selection is theory as to still scientific theory/research is still ongoing and changes can be made in a different direction.