Which Is TRUE of Gestalt Psychology

Which is TRUE of Gestalt psychology?

A) Early Gestalt psychologists studied problem solving
B) The "whole" perspective makes it easier to accept their research at face value.
C) The effectiveness of the reductionist approach inherent in Gestalt problem-solving research could not be relied upon to produce valuable insights.
D) The definition of "goal" as the desired end-point or solution of the problem-solving activity is problematic.