The age of the mother is one of the risk factors considered in screening for Down syndrome. It is generally believed that the older the mother, the higher the risk of genetic abnormalities in the baby. When an extra chromosome 21 is in the egg, the fetus will Down syndrome develops. As women age, the risk of such abnormalities increases. Recently, some experts have begun to question this screening method, saying that genetic abnormalities are not just a matter of the woman's age. Which of the following, if true, would best support the aforementioned expert question? ['Sperm chromosome 21 may also stick to excess genetic material. The older the father, the higher the probability of errors in the sperm production process.', 'The focus of the baby\'s mental health problems does not seem to be the "absolute age" of the mother, but the "relative age" of the father and mother.', 'The uterus basically does not change with age. As long as the hormone levels are sufficient, the uterus of older women can also properly support the fetus.', 'Modern people are prone to genetic mutations due to the influence of the environment and living habits, and even healthy couples are at risk of having "Tang children".']