Why did Vicksburg surrender?

a. General Grant's attack of the city caused heavy casualties for the Confederates.
b. The city ran out of food and the people inside were starved into surrendering.
c. The city had no water and the people inside had to surrender.
d. The Confederate commander was ordered by Jefferson Davis to surrender to General Grant.

The city ran out of food and the people inside were starved into surrendering.

Explanation:

The siege of Vicksburg by the U.S military troops took about a year from 1862 to 1863. There were multiple cases of continuous conflict and bloodshed in the attempt of capturing Vicksburg.The surrender of the Vicksburg can be attributed to the lack of food and clean drinking water in the city. The rations for the soldiers had been cut off with the fall of Mississippi River. Both civilians and the Confederates suffered from hunger and malnutrition as food supplies and enforcement from outside closed.On account of this, the Confederates had to surrender to the Union.