Which of the Following Is True Regarding Whether Penny's Prohibition

Which of the following is true regarding whether Penny's prohibition of discussion regarding the union and the distribution of literature in support of the union was objectionable under federal labor law?

A) Penny could legally prohibit all discussion regarding the union as well as all distribution of literature in support of the union anywhere on her business premises.
B) Penny could legally prevent all distribution of union literature anywhere and anytime on her business premises, but she could not prevent any discussion regarding the union.
C) Penny could legally prohibit all discussion regarding the union anywhere and anytime on her business premises, but she could not prevent any distribution of union literature.
D) Penny could likely legally prohibit discussion regarding the union and the distribution of literature during work time, but not during nonwork time such as lunch periods in the employee break room.
E) Penny could not legally prohibit any discussion of the union or any distribution of literature on her business premises.