(a) The organizers of a conference want to survey attendees about the registration fee. Which of the following best describes a stratified sample of attendees?The organizers assign each attendee a different number. Using a random number table, the organizers draw 56 of those numbers at random.Then, the organizers select the attendees assigned to the drawn numbers. Every set of 56 attendees is equally likely to be drawn using the random number table.The organizers form 7 groups of attendees based on the attendees' employment statuses. Then, the organizers select 8 attendees at random from each group.(b) A botanist at a nursery wants to inspect the health of the plants at the nursery. Which of the following best describes a systematic sample of plants?All of the plants that are in one particular room at the nursery are easily accessible. So, the botanist selects the 72 plants in this particular room.The botanist forms 6 groups of plants based on the ages of the plants (in months). Then, he selects 12 plants at random from each group.The botanist takes a list of the plants and selects every 3rd plant until 72 plants are selected.The organizers form groups of 8 attendees based on the day the attendees registered. Then, the organizers randomly choose 7 groups and select all of the attendees in these groups.(c) Counselors at a college want to poll students about how much time the students spend studying. Which of the following best describes a random sample of students?The counselors use a computer program to draw 78 students at random and select these students. Every set of 78 students is equally likely to be drawn by the computer program.The counselors form groups of 13 students based on the students' majors. Then, the counselors select all of the students in 6 randomly chosen groups.The counselors take a list of the students and select every 3rd student until 78 students are selected.