Final answer:
Mary Elizabeth Mahoney graduated from the first nursing school in the United States, making her the first African American professional nurse. Her significant contributions to nursing set high standards for education and professionalism in the field.
Step-by-step explanation:
Mary Elizabeth Mahoney is noted for her groundbreaking contributions to nursing. She graduated from the first nursing school in the United States, which is the correct answer to the question, corresponding with option A. Mahoney's achievement is significant as she was the first African American to graduate from a nursing school in the U.S, and she played a pivotal role in establishing high standards for nursing education and professionalism.
It is important to acknowledge the barriers that Mahoney and many others faced during her time. Despite hurdles associated with racial and gender-based discrimination, her persistence and excellence paved the way for future generations of nurses of all backgrounds. Mahoney's legacy includes the advancement of professional nursing roles for women and the promotion of quality medical care for all.