The correct answer is the following.
The technological advancement that was developed in installations near
these cities during World War II was the following: The Atomic Bomb.
Yes, during World War II, the US military and the federal government worked on a secret project called "The Manhattan Project." The goal, to create an atomic bomb.
The main laboratory was located in Los Alamos, New Mexico, and the scientists that worked there were exclusively dedicated to developing nuclear weapons. Robert Oppenheimer was the director of the laboratory in Los Alamos, although the head of the project was a military official, General Leslie Groves. The works started in 1942 and the culmination of the project was the launching of the atomic bombs over Hiroshima and Nagasaki, Japan, in August 1945.
