Which of the Following Came About as a Result of the "Davenport

Which of the following came about as a result of the "Davenport v. Washington Education Association" case?

A) Public sector unions are not allowed to strike.
B) Public sector employees are allowed to take up to 20 weeks of unpaid leave for family reasons.
C) Public sector unions are required to obtain written consent from nonmembers they represent in a bargaining unit before spending fees collected from them for electioneering expenses.
D) Public sector employees are protected from being fired for failure to make political contributions and certain employees are forbidden to engage in political activities.