Mark the letter A, B, C or D to indicate the sentence that best combines the following pairs of sentences.Câu hỏi "This is the park. It was built in the 19th century." A. This is the park which was built in the 19th century. B. This is the park whose was built in the 19th century. C. This is the park that its was built in the 19th century. D. This is the park, where was built in the 19th century.