Which of these shows the level of complexity, from simplest to most complex? a. organism - organs - organ systems b. organs - organ systems - organism c. organ systems - organism - organs d. organs - organism - organ systems

Simplest ==> Complex

We are looking for what makes up the bigger thing.  

An organ is part of an organ system. It is simpler than a whole array of organs, combined together to make a system. Take your digestive system. Your stomach is one organ, but all the intestines that contribute to the decomposition of food is far more complex than just one organ.  

organ- organ system

Organ systems make up a whole organism. The human body is composed of several organ systems. These make up a far more complex aspect of nature. The human body is far more incomprehensible and amazing than one organ system.  

So, "B" is the answer. organs-organ systems-organism.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint

the fossil record provides evidence of a common ancestor to many species.