Answer:
B without doubt.
Step-by-step explanation:
Edit
I cannot believe that I have answered this question twice and gotten it wrong both times. The not is critically important. D is definitely a result of Sputnik. The only thing that wasn't is B. Americans (and Canadians) were terrified by the advent of Sputnik. It hardly raised their confidence. Thank goodness someone was awake enough to give you the correct answer.