Even though stomach cancer kills more people than plane crashes do, most people tend to assume the plane crashes cause more deaths. this misconception seems to arise from the since plane crash fatalities tend to be widely publicized and are therefore relatively easy for people to bring to mind.

I believe the answer is: representativeness heuristic

representativeness heuristic refers to the tendency that people have to making quick shortcut in judgement when facing uncertain situations. This false judgement often more influenced by our personal bias rather than actual objective thinking.

answer; i believe the correct answer is (a) the correlation between the cause variable and outcome variable is zero;

answer; when one group has an extremely high score at pretest;