How do I get the question correctly the concept seems confusing . Please help.

duistical Analysis 1 PAGE: 9 of 20 URSE: STAT 1000 EXAMINER: Various A reading specialist in a large public school system believes that the more time students spend reading, the better they will do in school. She plans a middle school experiment in which an SRS (simple random sample) of 30 eighth graders will be assigned four extra hours of reading per week, an SRS of 30 seventh graders will be assigned two extra hours, or reading per week, and an SRS of 30 sixth graders with no extra assigned reading will be a control group. After one school year, the mean grades from each group will be compared. Is this a good experimental design? (A)Yes B) No, because while this design may point out an association between reading and grades, it cannot establish a cause-and-effect relationship. (C) No, because without blinding, there is a strong chance of a placebo effect. (D) No, because any conclusion would be flawed because of blocking bias., (E) No, because grade level is a lurking variable which may well be confounded with the variables under consideration. The next two questions (24 and 25) refer to the following: A study is designed to investigate the effect of creatine supplements on the development of muscle fibres. Volunteers are first grouped based on gender. Within each group, the volunteers are assigned to either take creatine or a placebo. A trainer's assistant flips a coin to decide which treatment each