Answer: Experiment.
Explanation:
Suppose that we have two related variables, A (independent) and B (dependent)
We could design an experiment where we can manipulate the value of A at will, and we also can observe how the variable B changes.
This is called an experiment, where the objective is to see how the variable B is related to the variable A, and then try to make a model that explains this relationship.
The correct answer is Economic cycle.
The natural fluctuation in economy between the period expansion (economy growth) and contraction (recession) is known as the economic cycle.
The normal growth and downturn in the economy is the basic definition of Economic cycle.
During the time of expansion the investors seek to purchase companies and shares and during the time of contraction the investors look to invest and purchase the companies such as utilities and healthcare.
Scientists believe that at first these bears scavenged seal carcasses that had washed ashore, and gradually began to hunt the seals by waiting at the water's edge as the seals surfaced to breathe. This is believed to be an important step in the evolution of a new bear species, the polar bear
Over time the new polar bears were used to the cold climate and learnt how to fish, they then separated from the grizzly bears, they developed new creatures which would help them survive in one of the most dangerous climate.