While president truman ultimately made the decision to drop the atomic bombs, the manhattan project and the development of those bombs was a decision made by

The correct answer is Franklin D. Roosevelt.

The only reason why Truman was left to the decision to drop the atomic bomb was because Franklin D. Roosevelt passed away while in office (after being elected to his fourth term). Before this, Roosevelt was the one who developed the program for the Manhattan Project and he was also responsible for navigating the US through most of World War II. Truman was only president for roughly 4 months before having to make the deicision about the atomic bomb.

c) troops march forward in close formation against newer, more accurate weapons

they thoght they were going to nuke each other