Final answer:
Memorial Day focuses on remembering and honoring military personnel who died in battle, with origins dating back to Civil War commemorations led by African American women. It has become a day for the nation to reflect on the sacrifices made by soldiers across all wars. The correct option is D.
Step-by-step explanation:
The primary focus of Memorial Day, which is observed on the last Monday in May, is D) Remembering military personnel who died in battle. This day is set aside to honor those who made the ultimate sacrifice for their country while serving in the U.S. military. Historical origins of Memorial Day date back to the Civil War era, where commemorative events were held, and African American women played a pivotal role in forming clubs to bury the dead, thank African American soldiers, and support their communities. Over time, Memorial Day evolved to include the remembrance of fallen soldiers from all wars, epitomized by the National World War II Memorial in Washington, DC, which honors those who served during the conflict. The day serves as a reminder of the cost of war and the valor of those who died while serving their nation.