How is the poverty threshold calculated? A) The Social Security Administration multiplies the cost of the least expensive nutritionally sound food plan by three.
B) The Social Security Administration interviews families and asks them how much money they spend on food each year.
C) The Social Security Administration surveys economists and asks them to predict how much a healthy food plan costs.
D) The Social Security Administration multiplies the cost of food stamps for a family of four by the cost of living in a big city

B. Organizing the history of Mexico into three distinct units of time.

Explanation:

Periodization is the process of organizing or systematically arranging/ classing things in accordance to their time periods. This allows for easy classification or understanding of the tie periods and their aspects/ important facts.

This concept is useful for organizing the history of Mexico into three distinct units of time. As periodization deals with the time periods, this categorizing of Mexican history into the three sections will help in analyzing them according to their common characteristics. This study of the history of Mexico within different time periods will enable the readers to better understand the historical facts in a much easier and more compact way.

Thus, the correct answer is option B.