Final answer:
Great Britain and France used a policy of appeasement, while the United States passed Neutrality Acts to respond to Hitler's annexation of Austria.
Step-by-step explanation:
Great Britain, France, and the United States reacted to Hitler's 1938 annexation of Austria in different ways. Great Britain and France were concerned about Hitler's expansion but were reluctant to take military action to stop him. They opted for a policy of appeasement, agreeing not to interfere with Hitler's plans in Czechoslovakia in exchange for his promise not to seek further territory. The United States, on the other hand, passed the Neutrality Acts to avoid involvement in foreign conflicts.