In 1945, what concern did the Allies have about invading the Japanese mainland with ground forces?

The Allies expected an invasion of Japan’s mainland to be extremely costly because Japanese forces and civilians were likely to resist fiercely. They were especially concerned about the enormous number of casualties among both Allied troops and Japanese people. Therefore, the correct choice is “They were worried there would be too great a loss of life.”

AI-written and checked against the verified answer.