Final answer:
The diagram suggesting the United States had a strong economy in the 1920s is supported by the Dawes Plan, which reflects the U.S.'s ability to extend loans internationally and the period marked by economic prosperity and growth.
Step-by-step explanation:
The diagram related to the Dawes Plan suggests that the United States economy in the 1920s was experiencing rapid growth and prosperity. This economic strength is demonstrated by the U.S. banks' ability to loan money to Germany to help stabilize its inflationary economy. These loans were part of an international agreement to assist Germany in making reparation payments to Britain and France, which in turn used the money to repay debts to the United States. Moreover, the U.S. economy was further characterized by technological innovations, increased wages, low unemployment, and a sense of affluence during this era, signifying a period of economic prosperity rather than weakness or dependency on foreign aid.