In the past three years, the sales of Jetta computers have grown rapidly. In the same period, the brand ’s spending on television advertising has also increased significantly. Therefore, some people believe that the increase in sales of Jetta computers is due to Promotion effect. Which of the following is true that would weaken the above conclusion? ["Few buyers of Jetta computers notice the brand's TV commercials.", "Hongyuan computer is Jetta's main competitor, and its TV advertising is more invested.", 'Few people noticed the Jetta computer TV commercial.', 'The total demand for computers has increased significantly in the last three years.']