Mark,a Manager,approaches an Employee in His Cubicle to Speak to Him

Mark,a manager,approaches an employee in his cubicle to speak to him directly about his poor performance.He says,"You had better buck up or I'll be forced to put you on a performance improvement program." A possible disadvantage of this approach is that:

A) the juxtaposition between the environment and the verbal message may cause tension and confusion.
B) the lack of tact apparent in the approach may reflect negatively on Mark.
C) it may be considered beyond the scope of supervision.
D) the statement may elicit more responses and open the conversation up into a dialogue.
E) it will still keep a positive attitude even as Mark gives the employee a verbal warning.