The correct answer is B) the growth of the advertising industry.
The trend during the 1920s that this image reflects is the growth of the advertising industry.
What happened in the 1920s was the United States economy lived a period of growth and prosperity in what was known as "the roaring 1920s." People had the money to spend and the companies invested a lot of money on advertising their products. People buy on credit and this created a problem. Everything changed when the US stock market crashed on October 29, 1929, in what is known as the beginning of the Great Depression.