Under Which of the Following Circumstances Will the NLRB Allow

Under which of the following circumstances will the NLRB allow the union to hold an election?

A) if an election has been held within the last year
B) if the employees have a union and a valid contract with the employer
C) if the union has engaged in unfair labor practices
D) if the union can show that at least 30 percent of the employees are interested in joining the union
E) in C and D only