The operation overlord invasion is also known as
a. d-day.
b. barbarossa.
c. battle of berlin.
d. battle of rome.

The correct answer is A.

Operation Overlord was also known as D-Day.

During WWII (1939 - 1945 ) the battle of Normandy, which lasted from June 1944 to August 1944, resulted in the allied  liberation of Western Europe from Nazi Germany's control.

Codenamed Operation Overlord, the battle began on June 4 1944, a day that was also known as D-Day, when 156,000 American, British and Canadian Forces landed on five beaches along the heavily fortified coast of France's Normandy region. 

a phrase from a poem by ralph waldo emerson about the battle of lexington and concord. emerson's words read, “here once the embattled farmers stood / and fired the shot heard round the world.”

on november 6 and 7, 1917 (or october 24 and 25 on the julian calendar, which is why the event is often referred to as the october revolution), leftist revolutionaries led by bolshevik party leader vladimir lenin launched a nearly bloodless coup d'état against the duma's provisional government.