Under the NLRA, What Posting(s) to Social Media Would Be

Under the NLRA, what posting(s) to social media would be considered legally protected?

A) Beach pictures posted anonymously on your profile the day you called in sick
B) Embarrassing and defamatory information posted about a coworker
C) Rumors about your company's declining stock prices
D) Complaints about salary or working conditions
E) all of the above