Step 1: Understanding Konrad Lorenz's work.
Konrad Lorenz is known for his work in the field of ethology, especially for his discovery of the process of imprinting. Imprinting is a form of learning in which a young animal, during a critical period of development, forms an attachment to a specific object, often the first moving object it encounters, typically the mother. Lorenz demonstrated this with ducklings and geese.
Step 2: Explanation of other options.
(A) Habituation is a form of non-associative learning where an organism decreases its response to a repeated stimulus over time.
(B) Sensitization involves an increased response to a stimulus after repeated exposure.
(C) Reinforcement refers to a process in operant conditioning, not specifically associated with Lorenz's work.
Step 3: Conclusion.
The correct answer is (D) Imprinting, as it is the process Konrad Lorenz is most famously associated with.