Final answer:
The sentence that best supports Maya Angelou's important contributions is the one mentioning President Obama awarding her the Presidential Medal of Freedom, which signifies national recognition of her impactful work.
Step-by-step explanation:
The sentence from the article that best supports the idea that Maya Angelou made many important contributions is: In 2011, President Barack Obama awarded Angelou the nation's highest honor, the Presidential Medal of Freedom. This sentence highlights a significant national recognition that Angelou received, which reflects the impact of her work and contributions. The Presidential Medal of Freedom is awarded to individuals who have made exemplary contributions to the prosperity, values, or security of the United States, to world peace, or to other significant societal, public, or private endeavors. Receiving this honor signifies that Maya Angelou's work had profound importance and influence, solidifying her legacy as a major contributor to arts, culture, and civil rights.