Douglas's stand that people could exclude slavery by refusing to

pass laws protecting slaveholders' rights came to be known as
a. Douglas's Debate. c. the Freeport Doctrine.
b. the Slaveholder's Rights. d. Douglas's Doctrine.

The correct answer is c. the Freeport Doctrine.

The Freeport Doctrine refers to a position taken by Stephen Douglas during the Lincoln-Douglas debates in 1858. Douglas argued that people living in a territory could effectively exclude slavery by simply refusing to pass laws protecting the rights of slaveholders. This doctrine became one of the defining aspects of the Lincoln-Douglas debates and had a significant impact on the issue of slavery during that time period.

To find the answer to this multiple-choice question, you would need to have some knowledge of the historical context and events surrounding Stephen Douglas and his debates with Abraham Lincoln. One way to acquire this knowledge would be through studying U.S. history textbooks, reading historical articles or books, or watching documentaries or lectures on the topic. By familiarizing yourself with these sources, you can gain an understanding of the key points and concepts related to Stephen Douglas and his beliefs on slavery, which would allow you to correctly identify the Freeport Doctrine as his stand on the issue.