Pamela wants to learn more about the career preferences of students in her school. She interviews a number of students from the advanced science classes. Why is this sample likely to be biased?1.Advanced science students may not have clear career preferences.2.The numbers of boys and girls in the advanced science classes are not equal.3.Advanced science students are not representative of all the students in the school.4.It is too early for students to have career preferences while still in school.