For Each Question, Indicate Which Heuristic It Describes

For each question, indicate which heuristic it describes:
-After reading about the positive effect chocolate has on student performance,a teacher gives each student in a class a chocolate bar before taking an exam.15 out of 22 students in that class get an A on the exam.The teacher therefore concludes that chocolate enhances performance.

A) The representativeness heuristic.
B) The availability heuristic.
C) The confirmation heuristic.
D) The affect heuristic.