In recent decades, people have invented a variety of drugs to poison mice. However, it has been found that the method of placing mouse medicine in places where rats often go in and out is becoming less and less effective. Among such delicious foods for mice, mice will ignore these "delicious" foods. According to this phenomenon, the possible explanation is that the mice's sense of smell is extremely sensitive, and they can discern substances harmful to them from any complex odor. Which of the following is the strongest indication that the last explanation above is wrong? ? ['ouse rarely goes to places where mouse pills have been placed.', 'ouse samples any food and tastes for toxic substances before eating.', 'cientists have passed a series of tests to prove that some mice have developed resistance to some drugs.', 'lace the food without any medicine in the place where the medicine was previously placed, and the mouse will not move the food.']