Concept:Kohler is known for the 'Theory of Insightful Learning', which is a type of learning theory in psychology.
Explanation:Wolfgang Kohler, a German psychologist, proposed that learning can occur suddenly through insight, not just by trial and error.
He conducted experiments with chimpanzees placed in a room with food out of reach but with boxes and sticks available.
The chimpanzees initially tried random actions, but then suddenly they used boxes to reach the stick and pulled the food closer.
This sudden understanding of the problem's solution is called 'insight'.
It is a cognitive process where the solution arrives all at once, not through gradual conditioning.
Thus, Kohler's work falls under the Theory of Learning, specifically insightful learning.
Answer:D. Theory of learning