Final answer:
The film about Christopher Boyce and Andrew Daulton Lee, who sold secrets to the Russians, is 'The Falcon and the Snowman.'
Step-by-step explanation:
The film that concerns Christopher Boyce and Andrew Daulton Lee, two Americans who sold secrets to the Russians, is The Falcon and the Snowman. This film is a dramatic account of actual events that took place in the 1970s, depicting how Boyce, a former aerospace industry employee, and his childhood friend Lee became involved in espionage against the United States. The movie provides a narrative of the theft of classified information and its subsequent sale to the Soviet Union, reflecting the tension of Cold War espionage and the complexity of the characters' motivations and actions.