A Research has shown that patients' expectations of treatment effectiveness are affected by what a treatment provider is wearing. A white lab coat tends to increase their expectation of effectiveness. Gloria, a research assistant, had no preconceived ideas about her research project, but by chance she wore a white lab coat when working with experimental Group but jeans and a t-shirt when working with experimental Group 2. This created a confounding variable. This confounding variable was a

A. Random effect
B. Placebo effect
C. Selection effect
D. Experimenter effect

Which revision best removes the informal language from this passage? (1) you should totally hire me to be your front deskreceptionist at your veterinary clinic because i loveanimals. (2) not only have l owned a wide array of pets,have also volunteered for three years at the crater valleyanimal shelter. (3) this experience would allow me to customers keep their animals calm and controlled whilethey wait for their appointments.oa. change only sentence 3 to 'this experience would allow me to customers keep their animals in an appropriate state ofanticipation while awaiting their appointments.ob. there is no informal language, so no change is necessary.oc. change only sentence 2 to not only have i owned a wide array ofpets, i have also volunteered for two years at the crater valleyanimal shelterod. change only sentence to believe that have the potential tosucceed as a receptionist formour veterinary office because i loveanimals