Why did people name Cambridge the “city of Cambridge”?

Câu hỏi :

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions

“Where is the university?” is a question many visitors to Cambridge ask, but no one can give them a clear answer, for there is no wall to be found around the university. The university is the city. You can find the classroom buildings, libraries, museums and offices of the university all over the city. And most of its members are the students and teachers or professors of the thirty-one colleges. Cambridge is already a developing town long before the first students and teachers arrived 800 years ago. It grew up by the river Granta, as the Cam was once called. A bridge was built over the river as early as 875. In the fourteenth and fifteenth centuries, more and more land was used for college buildings. The town grew faster in the nineteenth century after the opening of the railway in 1845. Cambridge became a city in 1951 and now it has the population of over 100000. Many young students want to study at Cambridge. Thousands of people from all over the world come to visit the university town. It has become a famous place all around the world. 

Why did people name Cambridge the “city of Cambridge”?