Task: Question Answering
Input (English): Background Paragraph: The example of someone having a positive experience with a drug is easy to see how drug dependence and the law of effect works. The tolerance for a drug goes up as one continues to use it after having a positive experience with a certain amount the first time.[38] It will take more and more to get that same feeling. This is when the controlled substance in an experiment would have to be modified and the experiment would really begin. The law of work for psychologist B. F. Skinner almost half a century later on the principles of operant conditioning, "a learning process by which the effect, or consequence, of a response influences the future rate of production of that response.[39]. 
Story: The cocaine club met to discuss their experiences. They all said they always had a great experience using cocaine and used the same amount each time. They told how many times they used cocaine. Mary used it 2 times, Patricia used it 3 times, Linda used it 5 times, Barbara used it 10 times, Elizabeth used it 15 times, Jennifer used it 20 times, and Maria used it 30 times. 
Question: Who has a higher tolerance for cocaine: Jennifer or Barbara?
Output (English): Jennifer.