Answer:
The correct answer is D. Colossus was developed during World War II. It was the first military computer that cracked the German code.
Step-by-step explanation:
The Colossus machines were the first electronic computing devices used by the British to read German encrypted communications during World War II. Colossus was one of the first digital computers.
The Colossus machine was originally designed by Tommy Flowers at the Post Office Research Station, Dollis Hill. The prototype, Colossus Mark I, came into operation at Bletchley Park from February 1944. An improved version, the Colossus Mark II was installed in June 1944, and about ten Colossus were built until the end of the war.