Correction: April 8, 2016

An earlier version of this quiz misstated the answer to No. 1. It is “restraining communist military power and ideological influence,” not “creating alliances with recently decolonized nations.”

Correction: April 10, 2016

A Pop Quiz on Page 21 this weekend — practice questions from the Advanced Placement exam in United States history that the College Board revised after criticism — renders question No. 12 incorrectly. The question should read, “Muir’s position regarding wilderness was most strongly supported by which of the following” — not “most strongly opposed.” (Before the board’s revisions, the question read “opposed.”) And the answer to No. 8, on Page 22, omits the original question: “The conditions shown in the image came about most directly as a result of.”