Answer:
3. This will lead to a biased sample because the type of students who take Psychology and Law may be different from the type of students who take Introduction to Neuroscience
Step-by-step explanation:
Professor Kramer wants to measure the level of happiness of his students, and he wants to do so for both his classes. However, he will biased the survey simply because he is considering surveying only the students from one of his classes, who may be very different from the students from the other class.
If Professor Kramer wants to make a unbiased survey, he should either find a way to also apply the survey to the students from the other class, or change the goal of the research to measuring the happiness level of the Psychology and Law class students only.