Final answer:
The United States extended credit to Europe post-World War II through the Marshall Plan, which aimed at European economic recovery, infused $12 billion into the economy, and countered the spread of communism.
Step-by-step explanation:
The entity which extended credit to Europe to help with recovery after World War II was the United States. Under the Truman administration, the European Recovery Program, commonly known as the Marshall Plan, was proposed by Secretary of State George C. Marshall in 1947 and enacted through the Economic Cooperation Act in 1948. This plan involved an injection of about $12 billion ($147 billion in today's dollars) into the European economy to help rebuild infrastructure, restore industrial capacity, and prevent the spread of communism by fostering economic prosperity.
During this time, the U.S. economy was strong due to surplus in the balance of trade and exports to the Allied powers. The U.S. took a leading role in shaping the post-World War II international order to maintain global peace and economic stability. Meanwhile, the USSR presented its own aid program, the Molotov Plan, to support communist states in Eastern Europe as a countermeasure.
Answer: A) United Nations