The correct answer is option 1, Germany. In the 1950s, Germany emerged as the pioneer in promoting the concept of a `Social Market Economy.` This economic model aimed to combine the principles of both socialism and capitalism to create a balanced and socially responsible market system.

Option 2, France, did not introduce the idea of a Social Market Economy in the 1950s. France, however, did adopt certain elements of this economic model later on.

Option 3, the United States of America, did not originate the concept of a Social Market Economy in the 1950s. The U.S. primarily followed a capitalist economic system with a focus on free markets.

Option 4, the United Kingdom, did not introduce the idea of a Social Market Economy in the 1950s. The U.K. primarily followed a mixed-market economic system, combining elements of both socialism and capitalism.

In conclusion, Germany is the correct answer as it was the country where the idea of a `Social Market Economy` emerged in the 1950s.