A、Because of the transform of the traveling cars. B、Because of the cancellation of the daily travel mileage limit. C、Because of

As the Mid-Autumn Festival and National Day holidays are only weeks away, car rental companies are busy receiving orders from customers.(23)Business insiders say the auto rental market has been heating up for the past few years, and companies have all seen the demand rising sharply. Last year, the booking windows for the national holidays were opened at the beginning of September. All the popular rentals were booked up by mid-September.
    To meet the rising demand in recent years, car rental companies have been strengthening stocks. Riding Company, for example, has purchased more than 10 thousand mid-range passenger cars nationwide and the number in some big cities is three times higher than that of last year. Industry insiders say there are various factors pushing up the demand.(24)One of the factors is the recent State Council notice that suspending highway toll fees on passenger cars during the holidays including the National Day holiday. Most people think they can make use of the benefits.
     (24)Aside from the highway free-pass, car rental companies have also made some adjustments to their contracts to bring in more customers. One is the cancellation of the daily travel mileage limit. In the past, if you drove longer than 180 to 350 kilometers a day, you would end up paying about 2 yuan for each extra kilometer.(25)But now many car rental companies have abolished the clause so that customers can travel farther without having to keep an eye on the meter.
23. What is the trend of the car rental market?
24. What is the factor to push up the demand for renting cars?
25. Why can customers travel farther without having to keep an eye on the meter?