The answer is 4. Someone may disagree that this was his major accomplishment. And the other options are stated as fact
The answer is A, the rest don’t really seem reasonable. And during the middle ages it was a time for great process in arts and SCIENCE! And the only one involving science is A :))
Answer:
1. Secondary source2. New york3. About 6 million
Explanation: just did it trust me
It allowed the Union to shoot down the confederates from atop the hill.