The correct option is: "The weapon’s power should be demonstrated to Japanese officials prior to its use."
Two types of atomic bombs were developed simultaneously during the Second World War: a relatively simple ballistic-type fission weapon and a more complex implosion nuclear weapon. The fission design of the Thin Man pump proved impractical for use with plutonium, so a simpler weapon called Little Boy was developed using uranium-235, an isotope that constitutes only 0.7% of the uranium in natural state. Project workers had difficulty separating this isotope from uranium-238 because of its chemical and mass similarities. Three methods were used for the enrichment of uranium: by the use of calutrons, by gas diffusion and by thermophoresis. Most of these jobs were carried out at the Clinton Engineer Works in Oak Ridge, Tennessee.