(A) ** Communication Codes
(B) Radar
(C) Walkie Talkies
(D) War Jets
EXPLANATIONS BELOW
Concept note-1: -The navies of the world entered World War II with highly developed radio communication systems, both telegraph and telephone, and with development under way of many electronic navigational aids. Blinker-light signaling was still used.
Concept note-2: -Similar to radar technology, computers had been in development well before the start of World War II. However, the war demanded rapid progression of such technology, resulting in the production of new computers of unprecedented power.
Concept note-3: -ENIGMA encryption/decryption device The ENIGMA cipher machine was used by the German military in World War II. Messages typed into the machine were encrypted and then sent by Morse code. Based on earlier Polish code-breaking efforts, special-purpose machines in the US and Britain secretly broke the ENIGMA codes.
Concept note-4: -Radar, computers, penicillin and more all came out of development during the Second World War. Radar, computers, penicillin and more all came out of development during the Second World War. One of the most infamous World War II inventions is the atomic bomb.