1)which of these was an example of a union state that did not allow slavery?
a. maryland
b. missouri
c. ohio
d. texas
2)which one of these was not a confederate state?
a. kentucky
b. north carolina
c. texas
d. virginia
3)which statement best describes “border” states?
a. industrial free states
b. slave states in the union
c. free states who were neutral
d. states against slavery's expansion

The correct answer for 1 is C. Ohio

Ohio never had slavery because it was created according to the Northwest Ordinance as a state that is slave free. The other three had slaves and Texas even had them during the war since they didn't participate in it and they found a loophole in the Emancipation proclamation to keep having slaves.

The correct answer for 2 is a. Kentucky

Kentucky never seceded and joined the Confederacy but they wanted to and were even given confederate congress seats. However, the war ended and they remained a part of the Union just like they were before and during the war.

The correct answer for 3 is
b.slave states in the Union

These were states like Kentucky which were found at the border with the confederacy. They had slaves but had not seceded and did not join the Confederacy. When West Virginia broke from Virginia it became a border state too.