The correct option is D Pu bomb and U-bomb respectively
"LITTLE Boy" is the nick name given to the atomic bomb dropped on Hiroshima on August 6, 1945. It was Monday morning. Little Boy was dropped from the Enola Gay, one of the B-29 bombers that flew over Hiroshima on that day.
Just three days after the bomb was dropped to Hiroshima, the second atomic bomb called "Fat Man" was dropped to Nagasaki on August 9, 1945. Though the amount of energy generated by the bomb dropped to Nagasaki was significantly larger than that of the Little Boy, the damage given to the city was slighter than that given to Hiroshima due to the geographic structure of the city.