Huangshan, Anhui is one of the main tea producing areas in China, and there are many types of famous teas. When traveling in Huangshan, tour guides will always stop at several tea gardens and advise everyone to visit them, and it doesn't matter if you buy them, just go and see. For this reason, some tourists often have grievances, but this phenomenon persists and even worsens. Which of the following is most unlikely to be the cause of this phenomenon? ['Tourists shop at the tea plantation and the tour guide gets a commission.', 'Although some tourists are not willing, many tourists are willing, and their happy shopping is the best proof.', 'Tourists to Huangshan are economically affluent. They just want to save time and enter the tea plantation to purchase in bulk.', 'One of the tasks of some tourists going out is shopping. If you return empty-handed, you will feel unhappy.']