题目：In the following text, identify the sentence that contains a logical inconsistency.
A. The new policy was designed to reduce traffic congestion, but it has actually increased the number of cars on the road.
B. The company claims to have the best customer service, yet many customers have reported long wait times.
C. The study found that exercise improves mental health, so it's recommended to exercise regularly.
D. The museum is closed on Mondays, but the sign outside says it's open every day.
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