The important result of the Union victory at Vicksburg was that the Union now controlled the Mississippi River. The correct option among all the options given in the question is option "A". This also helped the Union to cut off most of the Western States from the hands of the Confederate army. Also the Union had the control over the food supplies and this made the Confederate army surrender quickly.
Answer: Vivian and Janet have encountered the need for explanation, a challenge to intercultural relationships.
Explanation:
Vivian, as an African American, has to explain how she became friends with Janet, an European American, because people assume that cultural differences between African Americans and European Americans are too big to be overcome.