Question

which country was the last to join the allied powers?
○ great britain
○ france
○ united states
○ china

Explanation:

To determine the last country to join the Allied Powers (in the context of World War I or II, here likely WWI or WWII; for WWI, the US joined later, and for WWII, the US also joined later relative to the initial Allies). Great Britain, France, and China (or its wartime government) were part of the Allies earlier. The United States entered the war (and thus the Allied Powers) later than the others listed here (e.g., in WWI, the US joined in 1917, after Britain, France, and China's involvement had begun; in WWII, the US joined after the initial Allied declarations post - Pearl Harbor, but among these options, the US was the last to join the Allied Powers as a major combatant).

Answer:

C. United States