Which of these is least associated with the 1920s?
a: flappers
b: football
c: jazz
d: speakeasies

Which of these is LEAST associated with the 1920s?
A: flappers
B: football
C: jazz
D: speakeasies

Of course jazz was VERY popular in the 1920s as it was at its big moments.

Speakeasies were originated from (1920-1933) so we have definite proof that those were of that time.

Flappers were a generation of young ladies in the 1920s from the West that usually wore short skirts, listened to jazz, etc.

So we have proof that the only plausible answer here is
   B : Football

Hope I helped!