States in central & Eastern Europe
B) Striking workers in Poland started the Poznan uprising. The Poznan protests, which took place in 1956, were several massive protests against the government of Poland, for workers to receive better job conditions, however the government met this with violent repression.
The correct answer is siege.
Gaining control of Vicksburg was essential to the Union's military strategy. Taking control of Vicksburg would allow the Union army to control the Mississippi River. The Mississippi River was the lifeline for the Confederacy, as this waterway allowed them to easily send goods and troops to different parts of the US. Controlling the river would help the Union to stop the Confederacy from being able to transport goods. Along with this, it would also cut off Confederate states (like Texas) from other Confederate states located along the Atlantic Ocean.