Answer:
B. Referencing the new frontier of space.
Step-by-step explanation:
Kennedy builds trust with his audience by referencing the new frontier of space as a goal that the United States should strive to achieve. By framing the goal in terms of exploration and progress, Kennedy inspires a sense of adventure and excitement among his audience. This helps to establish a sense of shared purpose and commitment to achieving the goal, which in turn builds trust and support for the efforts to put a man on the moon. Additionally, by highlighting the potential benefits of space exploration, Kennedy also helps to alleviate concerns about the risks and expenses involved in the endeavor.