Plz, plz . i really need don't know what the answer is?
which of these is the best summary of the second paragraph?

on july 20, 1969, apollo 11 became the first manned mission to land on the moon. the mission involved astronauts neil armstrong, buzz aldrin, and michael collins. armstrong’s first steps on the moon were accompanied by his historic words: “that’s one small step for man, one giant leap for mankind.”
the landing fulfilled the goal set by president john f. kennedy eight years earlier. he wanted the united states to make it to the moon within the decade. he believed this to be an important accomplishment in the space race against the u. s.s. r. kennedy said, "we choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard."
on the moon, astronauts armstrong and aldrin experimented with various methods of movement in the diminished gravity. long leaping steps seemed to work best for moving about. they explored the surface for about two hours, collected 47 pounds of lunar samples, and planted the american flag on the moon’s surface. the crew safely returned to earth a little over eight days after leaving.

a.
american chose to go to the moon in the 1960s and to do other things because they were hard and not easy.

b.
president kennedy said that it was important for the america to stay ahead of the u. s.s. r. in the space race.

c.
the landing fulfilled president kennedy's goal and kept america ahead in the space race with the u. s.s. r.

d.
the moon landing of the apollo 11 was important because it fulfilled the goal set by president kennedy.