Answer:- 
Solution:- It is a simple unit conversion problem. We could solve this using dimensional analysis.
We know that, 1 US dollar = 100 cents
1 cent = 1 US penny
So, 1 US dollar = 100 US pennies
Let's make the set up starting with 1 penny as:
=
Therefore, we can bye of Cf in one US penny.
Sorry this will probably be pretty long.
So think of the "control" as being something you yourself add to increase or decrease the effects in an experiment.
I'll give you an example so it is not as confusing.
Say you have decided to make an experiment on plants. Which plant can grow the fastest on which type of liquid? What is being added to this experiment? The liquid! Or all of the liquids you used. Like if you used Coke, Lime Gatorade, Orange Gatorade, and Water. Each drink will EFFECT each plant differently.
Hope I was of any hope?
The answer to this ? is true
The answer is option C.
That is it is a heterogeneous mixture.
Heterogeneous mixture have the following properties:
1. Different components could be observed in the substance.
2. Different samples of the substance appeared to have different proportions of the components.
3.The components could be easily separated using filters and sorting.
