Part A
The author’s point in this paragraph is:
Katherine’s contributions help make the Friendship 7 mission happen and to establish the United States as leaders in space.
Part B
The evidence that best supports the answer to Part A is:
"Glenn’s flight was a success, and marked a turning point in the competition between the United States and the Soviet Union in space."
This statement highlights the impact of the mission, which is linked to Katherine's contributions, emphasizing the significance of achieving success in the context of space leadership.