Final answer:
The subject of this question is History, and it is asking about the most valuable double agent during the Cold War in the West. Double agents were individuals who secretly worked for two opposing intelligence agencies during the Cold War.
Step-by-step explanation:
The subject of this question is History. The question is asking about the identity of a person who was the most valuable double agent during the Cold War in the West.
Based on the given information, it is difficult to determine the specific identity of the person mentioned in the question. However, double agents were individuals who secretly worked for two opposing intelligence agencies, providing information to one side while pretending to be loyal to the other.
During the Cold War, there were several notable double agents who operated in the West, including Oleg Gordievsky and Aldrich Ames. These individuals betrayed their respective countries by passing sensitive information to the Soviet Union.