Question

In order to survive, organisms must maintain stable conditions in their bodies, even though their external environments are always changing.
For example, humans need to maintain an internal temperature around 37°C. Blood needs to have a pH around 7.4 and an oxygen saturation close to 100%.

What needs to happen in order to maintain these conditions?

A) Organ systems must interact with one another.
B) Organisms must be at rest.
C) Genes must be altered each time cells replicate.
D) All of these.

Answer 1

Your answer is A. Organ systems must interact with one another. 
Hope I helped :)

Answer 2

For humans (and other organisms) to maintain a constant internal temperature, pH, etc., we have to maintain homeostasis. The way our bodies maintain homeostasis is through our organ systems; they carry out processes which ensure we remain the same. Their interaction is vital to this process.

Answer:
A) Organ systems must interact with one another.