Question

The Supreme Commander of the Western Allies in the European Campaign was

A. General Dwight Eisenhower
B. General George Patton
C. General George Marshall
D. General Bernard Montgomery

Answer 1

General Dwight Eisenhower

Answer 2

I hope this helps you understand better!
"General Dwight D. Eisenhower was appointed commander of Supreme Headquarters Allied Expeditionary Force (SHAEF). General Bernard Montgomery was named commander of the 21st Army Group, which comprised all of the land forces involved in the invasion." (Wikipedia)