Which of these could be regarded as an advantage of complexity in higher organisms?

An advantage of complexity in higher organisms is that cellular differentiation leads to internal structural specialization. This means that different cells and tissues within an organism can perform specific functions that are necessary for the organism's survival. For example, in humans, the heart is made up of specialized muscle cells that are responsible for pumping blood throughout the body, while the lungs are made up of specialized cells that are responsible for gas exchange. This specialization allows organisms to perform more complex tasks and functions than simpler organisms that lack such specialization. Therefore, complexity in higher organisms allows for greater adaptability and survival in changing environments.