Option 1: Germany declared war on Britain. This option is incorrect. D-Day did not involve Germany declaring war on Britain. D-Day refers to a specific event during World War II, and it does not involve Germany making any declarations of war on Britain.

Option 2: US dropped the atom bomb on Hiroshima. This option is incorrect. D-Day refers to the Allied invasion of Normandy during World War II and has no connection with the dropping of the atomic bomb on Hiroshima.

Option 3: Allied troops landed in Normandy. This option is correct. D-Day, which occurred on June 6, 1944, was the day when Allied forces, including American, British, and Canadian troops, carried out a massive amphibious invasion of German-occupied France at the beaches of Normandy. This event marked a turning point in the war and helped the Allies gain a foothold in Europe.

Option 4: Germany surrendered to the Allies. This option is incorrect. Although the D-Day invasion contributed to the eventual surrender of Germany, it did not directly lead to Germany surrendering to the Allies. The surrender of Germany came about almost a year later, on May 7, 1945.