Medical Wonders Is a Specialized Interior Design Company Focused on Healing

Medical Wonders is a specialized interior design company focused on healing artwork.The CEO,Kathleen Kelledy claims that artwork has healing effects for patients staying in a hospital,as measured by reduced length of stay.Her current client is a children's cancer hospital.Kathleen is interested in determining the effect of three different pieces of healing artwork on children.She chooses three paintings (a horse photo,a bright abstract,and a muted beach scene) and randomly assigns six hospital rooms to each painting.Kathleen's null hypothesis 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