Question

a video game awards players with random bonus items after an unpredictable number of enemy defeats. sometimes a player gets a reward after five enemies, other times after twenty or more, but the rewards keep them playing. this pattern of reinforcement is based on a ______ schedule
fixed interval
variable ratio
fixed ratio
variable interval

Explanation:

In operant conditioning, a variable - ratio schedule means reinforcement is given after an unpredictable number of responses. Here, the reward (bonus item) is given after an unpredictable number of enemy defeats (responses). A fixed - interval schedule is based on time, a fixed - ratio on a set number of responses, and a variable - interval on an unpredictable time.

Answer:

B. variable ratio