While Reviewing Staffing Plans for a New Pilot Plant, Colin $\mu$

While reviewing staffing plans for a new pilot plant, Colin Posein, VP of Operations at Balzac Chemicals, Inc., designed an experiment to test the effects of "supervisor's style" and "training method" on the productivity of operators.The treatment levels were: (1) authoritarian, and participatory for supervisor's style, and (2) technical manuals, training films, and multimedia for training method.Three qualified applicants were randomly selected and assigned to each of the six cells.Colin's null hypothesis for training methods is ___.

A) $\mu$ ₁= $\mu$ ₂= $\mu$ ₃
B) $\mu$ ₁ $\neq$$\mu$ ₂ $\neq$$\mu$ ₃
C) $\mu$ ₁ $\ge$ $\mu$ ₂ $\ge$ $\mu$ ₃
D) $\mu$ ₁ $\le$ $\mu$ ₂ $\le$ $\mu$ ₃
E) $\mu$ ₁ $\le$$\mu$ ₂ ≥ $\mu$ ₃