Read the following passage about the Great Wall of China and mark the letter A, B, C, or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 18 to 22

The Great Wall of China, standing as one of the most remarkable wonders of the world, is a testament to ancient engineering and human perseverance. The Wall, built over several dynasties, ___(1)___. Initially constructed to protect against invasions and raids, it now symbolizes the strength and unity of the Chinese people. The Wall winds through rugged mountains, forests, and deserts, ___(2)___.
Designed with an intricate network of watchtowers, gates, and fortresses, ___(3)___. This massive structure reflects the combined efforts of countless workers and artisans who dedicated their lives to its construction. Today, the Wall's sections remain well-preserved and mostly intact. Therefore, ___(4)___.
Visiting the Great Wall offers more than just a view of its grandeur. Tourists can experience the culture, history, and stories of bravery linked to its existence. Infused with centuries of history, ___(5)___, qualities that continue to inspire people worldwide.