Answer:
D). Confirmation bias.
Step-by-step explanation:
Confirmation bias is characterized as the fallacious tendency displayed during a research in which the researcher searches, evaluates, or interprets the information favoring or confirming to the subsisting beliefs.
In the given situation, the researchers' display 'confirmation bias' as they are attempting to prove the existing beliefs about the students being gifted or not and studies and interprets the information accordingly. This inductive reasoning causes errors in the research that affects the validity and credibility of the results produced by the research. Thus, option D is the correct answer.