The answer is A.
If the bicipe muscle contracts it will bring the forearm up because the insertion of this muscle is in the forearm.
One of the functions of this muscle is flexing the elbow, which would result in the action i already mentioned.
It couldn't be B, because that would be the work of another muscle, the triceps.
Answer is the first option Place a metal paper clip on a table and slowly bring each electromagnet closer to the paper clip to see which can attract the paper clip from a greater distance.
I don't know why but I find your questions a bit too easy..
Insulin receptors regulate glucose level in blood. without that, glucose level would be uncontrolled/not normal (high/low) and it would be impossible to maintain homeostasis (stability) :P hope it will help.. :))
I would guess it just means that the population just stays the same, no growth.
The answer is germination :)