Studies have proven that the bone soup prepared by the traditional method has a low free calcium content, and the calcium content in each 100 ml of bone soup is only about 2 mg, so the traditional concept of "drinking bone soup to supplement calcium" is wrong. Which of the following, if true, best supports the above conclusion? ['Only free calcium can be digested and absorbed by the body.', 'The bone soup contains fatter, drinking bone soup often may cause hyperlipidemia.', 'The bone soup contains collagen, which can enhance the human hematopoietic function.', 'The calcium intake of Chinese residents is generally insufficient, and food supplements are the most convenient.']