Part A:
The best summary of the central idea included in the speech is:
B. President Kennedy would like all Americans to think about positive ways they can contribute to the country's goals of peace, strength, and concern with humanity.
Part B:
The detail from the speech that best supports this answer is:
D. And so, my fellow Americans: ask not what your country can do for you—ask what you can do for your country. My fellow citizens of the world: ask not what America will do for you, but what together we can do for the freedom of man.