Answer: D: Instinctive.
Step-by-step explanation:
The behavior shown by the birds is instinctive.
Instinctive behavior is a type of behavior that is inherent or innate, meaning that it is not learned through experience or practice. Instinctive behaviors are usually associated with survival, such as finding food and shelter, and they are often triggered by certain stimuli in the environment.
In this case, the birds are exhibiting an instinctive behavior by flying in and sitting on the power lines when the feeders are filled. They are attracted to the food and are following their natural instincts to find and consume it. This behavior is not learned or acquired through experience, but rather is a natural response to the presence of food.