Final answer:
The Manhattan Project, commanded by General Leslie Groves, was created in 1942 with the goal of developing a deliverable atomic bomb. It successfully detonated the first atomic bomb in July 1945.
Step-by-step explanation:
The correct answer is Manhattan Project (a). The Manhattan Project was a top-secret research project launched in 1942 at the beginning of World War II. It was commanded by General Leslie Groves, and its goal was to create a deliverable atomic bomb. The project employed over 100,000 people in various capacities, and successfully detonated the first atomic bomb in July 1945.