Final answer:
The largest startle response would occur if you had been watching a horror movie, as the tension and anticipation it creates can amplify your reactions to sudden noises like loud knocking.
Step-by-step explanation:
Startle Response and Movie Genres
You would likely show the largest startle response if you had been watching a horror movie when someone starts knocking on your door very loudly. This reaction is due in part to the heightened state of tension and anxiety that horror films often evoke, which primes you for a stronger startle reflex. Films create an immersive environment where the music, mood, and anticipation of what could happen next all contribute to this heightened state of alertness. For example, loud or sudden noises in these movies can parallel the unexpected knocking, triggering a more pronounced startle reaction, as the body's autonomic nervous system prepares for a potential emergency.