What amendment extended suffrage to nearly half of all american citizens? why did it affect so many?

Which situation would be considered an example of the freedom of association? a. three students write a letter to a local newspaper demanding that a teacher be fired. b. a group forms on a college campus to support a particular political candidate. c. an individual purchases a membership to a local gym. d. a religious organization buys several local lots in order to construct a new church building.