The school held a broadcast gymnastics competition in the grade. There are classes in the whole grade, each class has 100 students. It is stipulated that each class should take 100 students to participate in the competition. At this time, the sample size is () A. 13B.50C.650D.325 Answer D. Students from a famous school in a city take the exam. In order to understand the examination situation, the scores of 100 students were selected for statistical analysis. In this question, there are three kinds of views: ① candidates. 2 candidates are the whole; (3) Sample size is one of the correct statements: (a) 0 kinds of B. 1 C.2 kinds of D.3 kinds of answers B.1In order to understand the views of all the students on teachers, the school conducted a questionnaire survey on all the students; ② In order to know the junior high school students' online situation, the Youth League Committee of a city conducted a survey on some students in the junior high school; ③ A class of students plans to organize a spring outing. In order to determine the location of the spring outing, the students were investigated. (4) In order to know the homework completion of the whole class, an odd number of students were investigated. In the above survey, the answer a is () a.13b.12c.24d.23answer a.