The 1920s is marked as a period of new inventions. The electric refrigerator was created replacing the icebox which, as its name implies, used blocks of daily shipped ice to keep food cool. Emerging companies transported frozen food across the nation in refrigerated railway trains that utilized a newly developed coolant called sulfur dioxide. Purchasing already prepared frozen food was a widely adopted practice because it shaved hours off of food preparation times. Art exploded as well during the 1920s. A new form of improvised music known as jazz replaced ragtime music that had been popular from the late 1800s until the 1910s. Rather than the common household practice of purchasing piano sheet music and singing along to the melody, Americans enjoyed listening to records from jazz artists such as Count Basie, Louis Armstrong, and Dizzy Gillespie. The 1920s was also the period of alcohol prohibition. Decades of public outcry about the effects of overconsumption of liquor led to strict laws that prohibited its sale during the 1920s. Bootleggers illegally manufactured liquor and sold it to citizens with one of the most famous of them being Al Capone. Alcohol prohibition laws were repealed in 1933. What reason best explains why frozen foods became popular?

a. They are convenient. ​

b. They are less expensive. ​

c. They are easier to obtain than fresh food.