Suppose we want to estimate the average weight of children in a particular school district. The district contains 15 elementary schools, 10 middle schools, and 2 high schools. For each of the following approaches, select the best description of the sampling design, and identify whether the sampling scheme ensures that the probability of being included is necessarily the same for every student. A. Take a simple random sample of 5 schools in the district. For each school in the sample, list the weights of all the students. Combine the lists and average the result. (Q5) (Q6) B. List all the schools in the school district. For each school, list all the teachers at the school; sort them alphabetically within each school. For each school, list the weights of the students of the teacher who is first on that school's sorted teacher list. Combine the lists and average the results. (Q7) (Q8) C. List all the students in the school district. Average the weights of every 50th student on the list. (Q9) (Q10) D. Take a simple random sample of 5 schools in the district. For each school in the sample, list all the homerooms. Take a simple random sample of 3 homerooms from each school in the sample. For each homeroom in the sample, list the students. Take a simple random sample of 10 students from each homeroom in the sample. List their weights. Combine the lists and average the results.