The correct answer is B) buying on margin.
The business practice that contributed to the trend that is shown in this graph is buying on margin.
The graph shows the Dow Jones Industrial Average increasing from 1922 to 1930. Buying on margin was the business practice that contributed to the trend. The negative side of this practice was that buying on margin contributed to the United States stock market crash on October 29, 1929, that caused the beginning of the Great Depression in the US. People were used to buying stock but not paying the full price. During the Great Depression, thousands of Americans lost their jobs, many companies closed, and n¿banks went into bankruptcy.