An Employer Is in the Process of Negotiating a New

An employer is in the process of negotiating a new contract with its union.During negotiations,the employer changed the workweek from a five-day,eight-hour-per-day week to a four-day,ten-hour-per-day week.Which statement is correct?

A) This is a violation of the National Labor Relations Act.
B) This is not a violation of the NLRA because the employer is bargaining with the union.
C) This is not violation of the NLRA because the total number of work hours per week has not changed.
D) Whether or not this is a violation of the NLRA will depend on the relevant state statutory law.