Which of the Following Is an Ideal Condition for a Free

Which of the following is an ideal condition for a free market?

A) There are no parties, institutions, or governmental units regulating the quantity of the goods being bought or sold in the market.
B) There are a few buyers and many sellers, and all of them have a substantial share of the market.
C) All the buyers and sellers in the market are free to leave the market but there are significant barriers to entering the market.
D) All buyers have full knowledge of what other buyers and sellers are up to including quantity of goods sold, but not the prices and quality of goods being sold.
E) The participants in the market have very strong preferences as to which seller or buyer they would deal with.