Final answer:
In this example, the conditioned stimulus is watching a movie. Sven has associated the act of watching a movie with eating popcorn.
Step-by-step explanation:
In this example, the conditioned stimulus is watching a movie. The reason is that Sven has associated the act of watching a movie with eating popcorn. Initially, popcorn was the unconditioned stimulus that caused Sven's mouth to water (unconditioned response). But over time, the neutral stimulus of watching a movie became associated with eating popcorn, and now it elicits the conditioned response of wanting popcorn.