Answer:
The invention of the printing press by Johannes Gutenberg.
Explanation:
The invention of the printing press by Johannes Gutenberg allowed new ideas to spread more quickly around Europe. The discovery of America by Columbus meant that new foods and medicines were brought back from the New World.
After the Civil War, Kansas was advertised as a good place for African Americans to settle. The 1859 Kansas Constitution opened the state to all settlers regardless of their ethnic or racial background. In the 1870 census blacks made up 4.6 percent of the state's population.
D is the correct answer
