Final answer:
The period referred to regarding the segregation of the army post-return is World War II, when African American soldiers continued to face discrimination at home despite their service.
Step-by-step explanation:
The event or period being referred to in the statement about the segregation of the army upon returning home after World War II is option B) World War II. During WWII, the United States military was officially segregated, and African American soldiers fought in all-Black units. When they returned home after the war, many of these soldiers found that despite their service and sacrifices, segregation and discrimination persisted, and they were not granted greater rights. This situation, among other factors, contributed to the Civil Rights Movement that gained momentum in the ensuing decades.