单项选择题

In ancient times, the most important examinations were spoken, not written. In the schools of ancient Greece and Rome, testing usually included saying poetry aloud or giving speeches.
In the European universities of the Middle Ages, students who were working for advanced degrees bad to discuss questions in their field of study with people who had made a special study of the subject. This custom exists today as part of the process of testing candidates(考生) for the doctor’s degree.
Generally, however, modern examinations are written. The written examination, where all students are tested on the same questions, was probably not known until the nineteenth century. Perhaps it came into existence with the great increase in population and the development of modern industry around the 19th century. A room full of candidates for a state examination, timed exactly by electronic clocks and carefully watched over by managers, is like a group of workers at a car factory. Certainly, during examinations teachers and students are expected to act like machines.
One type of test is sometimes called an objective test. It is intended to deal with facts, not personal judgments. To make up an objective test the teacher writes several questions, each of which has only one correct answer. Along with each question the teacher writes the correct answer and also three statements that look like answers to students who have not learned the material properly.
Modem industry must have developed ______.

A. before the Middle Ages

B. in Greece or Rome
C. around the 19th century

D. until the 19th century