This is the name for a category of trade barriers that a country may impose on another country or countries.
This

answer; the government can clearly justify the restriction;

representative sample

sociologists study the world, observe a predicament or interesting design, and set out to investigate it. they use investigation methods to design a study possibly a comprehensive, detailed and precise, by using experimental method for directing research and gathering data.

to study the characteristics of the whole population, sociologist prefers to obtain the sample which is the finite part of a demographic population whose characteristics are analyzed to obtain data from statistics.

when administering with population, it can be described as a set of respondents picked from a larger population for the goal of a survey. a population could be a group of objects, people, or articles from which samples are obtained for computation of the whole population which is the aim of the sociological study.