What Role Does the NLRB Play in a Representation Election

What role does the NLRB play in a representation election?

A) it supervises the election
B) it tells employees about the costs and benefits of unionization for an unbiased view
C) it certifies the election results
D) it supervises the election and certifies the election results
E) supervises the election and certifies the election results and tells employees about the costs and benefits of unionization for an unbiased view