You didnt list the choices but I know the anwser.
<span>It was the heir to the Austro-Hungarian throne
his assassination was the spark that ignited World War I.</span>
Answer: 3. variable ratio
Options:
1. fixed interval
2. fixed ratio
3. variable ratio
4. variable interval
Explanation: The variable ratio of reinforcement uses rewards to create a high and steady rate of response. The rate of reward for a target behavior is unpredictable so the rat does not know when its response will get a reward. It will keep responding until the reward is delivered.
The options listed above are schedules of reinforcement. They are schedules used in rewarding target behavior in Operant conditioning.
You didn't include the options, but Brazil was one nation that gained independence in 1822.
