9. suppose that species a evolves and species b evolves in response to the changes in species a. species a then changes in response to the changes in species b. this is an example of

a. convergent evolution.
b. extinction.
c. adaptive radiation.
d. coevolution.

Correct D). Co-evolution

The co-evolution is the process of reciprocal revolutionary changes that are known to occur between the two or more species. The activity of each species, which participate in the interaction, applies a selection pressure to the others. It is one of the primary methods by which biological communities are organized.  

Example: Predator-prey relationship, in this relationship, there is selective pressure on prey in order to avoid capture. As a result of that, the predator must adapt to become a more effective hunter.

Hence, the correct answer would be option A.

the function of the protein macromolecule is to move things in and out of the cell and transport other molecules in the body. there are many functions of proteins. they are the basic building blocks of living things and are responsible for the growth and repair of body cells and tissues.

explanation: