The correct answer is option 1: August 6, 1945. On this day, the United States dropped an atomic bomb named "Little Boy" on the city of Hiroshima, Japan, during World War II. The bombing resulted in the immediate deaths of approximately 80,000 people and thousands more died later due to radiation exposure. This was the first time in history that an atomic bomb was used in warfare. The bombing of Hiroshima played a significant role in ending the war, as Japan surrendered shortly after the bombing of Nagasaki on August 9, 1945. The bombings of Hiroshima and Nagasaki remain controversial to this day due to the immense loss of life and long-term effects of radiation exposure.