How did the Kansas territory decide whether they will be a slave or free state?

A. 36-30 line of Missouri Compromise

B. U. S. Congress decided

C. Canada decided

D. Popular Sovereignty

Kansas territory decide whether they will be a slave or free state through popular sovereignty.

Option: D

Explanation:

Popular sovereignty has become mandatory by the Kansas - Nebraska act. This act made a bill in 1854 to decide whether the citizen of Kansas territory would be a slave or it would be a free state. After a great war it was decided that Kansas would be a free state in the Union.

The slave forces that want to make citizen slaves was the cause of American civil war. If Kansas follow the slavery system it will violate the Missouri compromise. That's why it was decided by the popular sovereignty that Kansas would be a free state.