Answer:
D). I believe that this nation should commit itself to achieve the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth.
Step-by-step explanation:
President Kennedy in his declaration speech employed the term 'space race' to declare the specific goal of 'landing on the moon' before the Soviet Union. The last statement regarding the president's belief that the nation should display commitment towards attaining the goal of landing on the moon before the decade gets over most aptly supports the 'space race' that was going on. Thus, option D is the correct answer.