Final answer:
Winston Churchill replaced Neville Chamberlain as the British Prime Minister during World War II.
Step-by-step explanation:
Winston Churchill replaced Neville Chamberlain as the British Prime Minister during World War II. Chamberlain's policy of appeasement, as seen in the Munich Agreement, had failed to prevent Hitler's aggression. Churchill, known as the 'Bulldog,' was chosen for his strong leadership and his belief in standing up to Hitler rather than appeasing him.