A survey of patients with congenital heart disease in a county in the north showed that most of the patients were born in winter. Experts point out that the cause is likely to be malnutrition of pregnant women who are giving birth, because during the coldest season of the year It is difficult for people to buy fresh food. Which of the following, if true, can support the conclusions of experts in the topic? ['A considerable percentage of patients in the survey have a family history of genetic disease.', 'Congenital patients account for a small proportion of patients with heart disease.', 'Development of cardiovascular areas associated with heart disease, most of which occur one month before delivery.', 'The nutritional content of fresh foods and preserved foods has the same effect on cardiovascular development.']