A university professor believes that since the implementation of China's housing provident fund system, only some deposit-paying employees who have the ability to buy a house have enjoyed low-interest housing loans, and it has not played a role in housing security for those working-class workers with low income and no ability to buy a house. Therefore, the housing provident fund system is a "robbing the poor and helping the rich" system, and the state should cancel the housing provident fund system. Which of the following, if true, would most weaken the professor's point of view? ['The housing provident fund system is a compulsory housing security system established by the state.', 'The provident fund of the enterprise deposit is an additional income for the individual.', 'Deposit workers of private enterprises do not have the ability to purchase a house due to low income.', 'Migrant workers are generally unwilling to buy a house at work.']