Answer:
The correct answer is option b. "The interior cells are exposed to a different physical and chemical environment than the exterior cells".
Explanation:
Complex multicellularity is a characteristic that large organisms comprised of thousands of cells posses. The organisms with complex multicellularity have their cells organized into different tissues in a three dimensional arrangement, that often involves the development of organs. One characteristic of complex multicellularity is that the interior cells are exposed to a different physical and chemical environment than the exterior cells. For instance, skin cells have adapted to serve as a barrier to pathogen and environmental conditions, while blood cells have adapted to transport nutrients and serve in the immune system.
