Which of the Following Statements Is True of Union Decertification

Which of the following statements is true of union decertification?

A) A union can be decertified only if it is being pressured by the government to do so.
B) A decertification election is conducted when 30 percent of the eligible employees in the bargaining unit sign the decertification cards.
C) For decertification to occur, a closed-shop agreement must have existed between the union and the employer.
D) Once a union has been decertified, a new election cannot be requested for certification for at least 2 years.