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.

the "dirty dozen" chemicals banned in an international treaty are formally known as persistent organic pollutants, or pops. the united nations environment program provided this background on what they are and what they can do to humans and wildlife.

i hope this