Which of the Following Is an Unfair Labour Practice

Which of the following is an unfair labour practice?

A) An employer threatens to have an employee fired if he joins a union.
B) An employer starts another unrelated business that is non-union, as a union tries to organize his employees at the present location.
C) An employee is required to join a union as a condition of employment.
D) An employer pays higher wages as part of his annual wage increase, as a union is trying to organize his employees.
E) A union representative has a conversation with an employee about joining the union.