(1) During the Spanish-American War, U.S. soldiers were supplied with tin cans containing decayed meat. (2) Due to a lack of food safety standards, vendors in the 1800s often sold food that would not today be considered fit for people to eat. (3) Store-bought butter was often stale and mixed with gelatin, fat, and even mashed potatoes. (4) To improve the color of milk from diseased cattle, dairymen sometimes added molasses, chalk, or plaster of Paris. Which sentence is the point of the argument?