Mrs. Matthews contacted the Children's Center for her daughter, Diane, who is now 5 years old. As soon as Diane was born, her mother thought her daughter was "different." Mrs. Matthews reported that the pediatrician found Diane to be in good health and predicted she would eventually outgrow her odd behaviors. Unfortunately, that does not seem to be the case. Diane does not make eye contact when she speaks and grunts if anyone tries to get too close to her. Diane has certain routines. For example, she has to line up all her dolls in a certain way before leaving the house. If a routine is interrupted, Diane becomes extremely upset and aggressive; that is, kicking and punching anyone who tries to comfort her. Diane's diagnosis

What is the difference between an observational study and an​ experiment? choose the correct answer below. a. in an​ experiment, a treatment is applied to part of a population and responses are observed. in an observational​ study, a researcher measures characteristics of interest of a part of a population but does not change existing conditions. b. in an​ experiment, a treatment is applied to an entire population and responses are observed. in an observational​ study, a researcher measures characteristics of interest of an entire population but does not change existing conditions. c. in an​ experiment, a researcher measures characteristics of interest of a part of a population but does not change existing conditions. in an observational​ study, a treatment is applied to part of a population and responses are observed. d. in an​ experiment, a researcher measures characteristics of interest of an entire population but does not change existing conditions. in an observational​ study, a treatment is applied to an entire population and responses are observed.