Sally Fronson sent an e-mail to a co-worker on her employer’s e-mail system that read, "I have had it with the long hours, the wages, and the attitude. Let’s see if we can bring in a union." Which of the following is correct?​ a. ​Sally can be terminated for private use of her employer’s e-mail system. b. ​Sally’s e-mail is privileged and protected as union organizing and cannot be viewed by her employer. c. ​Sally’s e-mail is a permitted use and protected under the NRLA. d. ​Sally’s e-mail is private and cannot be viewed by her employer.