Read the following article and select the best answer. Article: In 1841, a book was published which astonished the world. It was called"Incidents of Travel in Central America, Chiapas and Yucatan". The author John Loud Stephens had just returned from a long, difficult and dangerous journey through the thick rain forest of southern prefix = st1 /MexicoandGuatemala. He had once been there with Frederick Catherwood, an architect and artist, to search for the remains of a lost civilization known as the Mayas .Very little was known about the Mayas at that time, but Catherwood's drawing in the book showed incredible cities with temples, pyramids and other buildings as impressive as those of their northern neighbors, the Aztecs. These cities, however, were deserted. The inhabitants had disappeared almost a thousand years before. Since that time, far more has been learned about this remarkable civilization. The Mayas had a highly developed system of government and of agriculture, as well as an incredibly accurate system of measuring time. They were also wonderful engineers capable of moving huge blocks stone long distances and cutting them to accurate shapes and sizes. And yet although the Mayas knew about the wheel, they never used it. Neither did they use metals other than copper. What is ever more surprising is that they suddenly abandoned many of their cities and built new ones in the jungle. Some time around AD900, Mayan civilization collapsed. By the year 1200, their last great capital,Chichen Itza, was deserted. Who were these strange people and the even stranger gods they worshipped ? What brought about their sudden and mysterious collapse? Some writers have tried to prove that the Mayas had contact with visitors from space and even that they themselves came from another planet. Some people believe that their civilization came to an end because the Mayas never developed a proper resistance to local germs and diseases. All we really know is that when the first Europeans appeared off their coast in 1517, this great and mysterious culture was only a memory. Question: Stephen's book astonished the world because_. - it was the first time people heard about Mayas - the Mayas were excellent builders and farmers - he had experienced so may difficulties to find this lost civilization - it described that the Mayas used to be an advanced civilization
The answer to this question is:
it described that the Mayas used to be an advanced civilization