Supply and demand is: A. an advertising principle that the value of a product is directly
proportional to how many public figures and celebrities use it.
B. an advertising method supporting the idea that if you show several
products being used in an ad, more people will want to buy them.
C. an economic idea that the value of something is determined
how much of it exists in relation to how much consumers want it.
D. an economic principle supporting the idea that the quicker
something is made, the sooner it can be sold on the open market.