According to statistics, the top three populations in a city are pharyngitis, hypertension, and diabetes. Among them, the incidence of hypertension and diabetes increases with age, and the incidence of pharyngitis in all ages is not obvious. In the next 10 years, the proportion of the elderly population in the city will increase significantly. Based on the information provided by the stem, which of the following is the most appropriate inference? ['After 10 years, the highest incidence will be hypertension.', 'After 10 years, the highest incidence will remain pharyngitis.', 'The average age of pharyngitis patients will increase over the next 10 years.', 'After 10 years, older patients will have more pharyngitis than non-elderly patients.']