Question

the land ordinance of 1785 affected slavery by stopping it from spreading. spreading it throughout the nation. abolishing it throughout the nation. allowing enslaved people to settle in the west.

Explanation:

The Land Ordinance of 1785 established a system for surveying and selling western lands, and it prohibited slavery in the Northwest Territory (the lands north of the Ohio River), which prevented slavery from spreading into that region. The other options are incorrect: it did not spread slavery nationwide, abolish it nationwide, or allow enslaved people to settle in the West.

Answer:

stopping it from spreading.