Each of the following is a true statement except: a. no nation has a pure market economy b. the black market appears in every nation c. communist nations have a total command economy d. a mixed market is the world’s most common economic system

Among the options given on the question the correct answer is option B.

Every statement given on the question is true except that the black market appears in every nation.

Explanation: Among the options the 1st statement is that no nation has a pure market economy.This is true because there is no existent of pure market economy. A pure market economy means that there will no control of the business by the government. But every nation has some regulatory activities in the business.

The 3rd statement is also true. The communist ruled nation's has total command economy. In this system the government holds the power to decide about anything of the market. There are hardly any power to the private sector.

The 4th statement is about mixed market economy. The mixed market economy is consist of both the pure market and command economy. This economic system is the most common system of the world.

But the 2nd statement is not true.Because the no nation allows the black market in their economy and it is a punishable crime. So the statement about black market is false.