Answer:
D. creating coded messages
Step-by-step explanation:
CIA field agents serve both information gathering and covert operations purposes. Some are spies and others are special operations specialists. CIA agents are present in nearly all foreign countries.
Working closely with the CIA is the National Security Agency (NSA). Like the CIA, the NSA was a spin-off from the original OSS. The organization specializes in cryptanalysis, the process of looking for patterns in coded or encrypted messages. Cryptanalysis depends on enormously powerful computers to perform these searches. A code-breaking operation in World War II was able to break the German Enigma code. This allowed the allies to track the positions of German U-boats and win the Battle of the Atlantic.