Higher organisms use a transport system and not diffusion only to distribute nutrients because?

A. the ratio of their surface area to volume is small
B. metabolic waste products diffuse to the surface of the organisms
C. the rate at which nutrients and other substances diffuse increases
D. substances to be transported move shorter distances to reach the numerous cells
E. the internal structures of the organisms are in direct contact with the environment.

Correct Answer:

Option A – the ratio of their surface area to volume is small