How did the loss of its control of the mississippi river contribute to the defeat of the confederacy?

The reason why the loss control of the Mississippi River contribute to the defeat of the Confederacy is:  Losing control of the river divided the Confederacy in two and cut off its supplies.

This make it easier for their enemies to weaken confederacy army and took them out when they have no energy or ammunition left.

d, e

Explanation:

a. (74) is not less than 50  

b. (26) + 24 = 50, which is not under 50

c. (76) is not less than 50

d (25) + 24 = 49, which IS less than 50

e. (2) + 24 = 26 which is less than 50

f. (148) is not less than 50