(A) ** Hiroshima
(B) Dallas
EXPLANATIONS BELOW
Concept note-1: -As president, it was Harry Truman’s decision if the weapon would be used with the goal to end the war. “It is an awful responsibility that has come to us, ” the president wrote.
Concept note-2: -Truman was elected vice president in 1944 and assumed the presidency following the death of Roosevelt. Now acting as president, Truman was informed about the ongoing Manhattan Project and the atomic bomb. Truman authorized the first and only use of nuclear weapons in war against Hiroshima and Nagasaki in Japan.
Concept note-3: -Obama, President of the United States of America, accompanied by Mr. Shinzo Abe, Prime Minister of Japan, visited Hiroshima, as the first sitting U.S. President to visit the city.
Concept note-4: -It contained military forces and military factories. The area was flat terrain extending in all directions. Therefore, Hiroshima’s topography and size were optimal for testing the destructive power of the atomic bomb and for verifying its effectiveness after the bombing.