Council member: The profits of downtown businesses will increase if more consumers live in the downtown area, and a decrease in the cost of living in the downtown area will guarantee that the number of consumers living there will increase. However, the profits of downtown businesses will not increase unless downtown traffic congestion decreases. If all the council member's statements are true, which one of the following must be true? ['If the cost of living in the downtown area decreases, the profits of downtown businesses will increase.', 'If downtown traffic congestion decreases, the cost of living in the downtown area will decrease.', 'If downtown traffic congestion decreases, the number of consumers living in the downtown area will increase.', 'If downtown traffic congestion decreases, the cost of living in the downtown area will increase.']