According to paragraph 1, which of the following best describes the progress made in the search for ruins of ancient Mesoamerica? A. The oldest remains were discovered immediately after Columbus arrived, and later findings correspond to more recent ruins. B. From the late eighteenth century through the twentieth century, increasingly older remains were found. C. All of the archaeological work was completed in the twentieth century. D. Technological developments made it progressively easier for explorers to discover Mayan cities in the jungle.