The city is a living body, a historical and cultural city, her life span is thousands of years, and the annual rings that confirm her life will definitely have thousands. The historical and cultural heritage as the city ring cannot be destroyed or discarded. Destroying or discarding the annual rings of a city is a characteristic of self-destructive cities, and a city can only have core competitiveness if it maintains its inherent characteristics. Based on the above statement, which of the following can be derived? ['Only by protecting historical and cultural heritage can historical and cultural cities have core competitiveness.', 'A city can protect its historical and cultural heritage only if it has core competitiveness.', 'If the historical and cultural heritage is protected, a city can have its core competitiveness.', 'If historical and cultural heritage is destroyed or discarded, historical and cultural cities will lose their vitality.']