Without most people realizing it, there has been a revolution in office work over the last ten years. Before that time, large computers were only used by large, rich companies that could afford the investment. With the advancement of technology, small computers have come onto the market, which are capable of doing the work that used to be done by much larger and expensive computers, so now most smaller companies can use them.        The main development in small computers has been in the field of word processors   , or WPS as they are often called. 40% of British offices are now estimated to have a word processor and this percentage is growing fast.        There are many advantages in using a word processor for both secretary and manager. The secretary is freed from a lot of daily work, such as re-typing letters and storing papers. He or she can use this time to do other more interesting work for the boss. From a manager's point of view, secretarial time is being made better use of and money can be saved by doing daily jobs automatically outside office hours.        But is it all good? If a lot of daily secretarial work can be done automatically, surely this will mean that fewer secretaries will be needed. Another worry is the increasing medical problems related to work with visual display units  . The case of a slow loss of sight among people using word processors seems to have risen greatly. It is also feared that if a woman works at a VDU for long hours, the unborn child in her body might be killed. Safety screens to put over a VDU have been invented but few companies in prefix = st1 /Englandbother to buy them.                                                                                          Whatever the arguments for and against word processor are, they are a key feature   of this revolution in office practice. Ten years ago, smaller companies did not use large computers because  _  .
these companies had not enough money to buy such expensive computers these computers could not do the work that small computers can do today these computers did not come onto the market these companies did not need to use this new technology
Question: Without most people realizing it, there has been a revolution in office work over the last ten years. Before that time, large computers were only used by large, rich companies that could afford the investment. With the advancement of technology, small computers have come onto the market, which are capable of doing the work that used to be done by much larger and expensive computers, so now most smaller companies can use them.        The main development in small computers has been in the field of word processors   , or WPS as they are often called. 40% of British offices are now estimated to have a word processor and this percentage is growing fast.        There are many advantages in using a word processor for both secretary and manager. The secretary is freed from a lot of daily work, such as re-typing letters and storing papers. He or she can use this time to do other more interesting work for the boss. From a manager's point of view, secretarial time is being made better use of and money can be saved by doing daily jobs automatically outside office hours.        But is it all good? If a lot of daily secretarial work can be done automatically, surely this will mean that fewer secretaries will be needed. Another worry is the increasing medical problems related to work with visual display units  . The case of a slow loss of sight among people using word processors seems to have risen greatly. It is also feared that if a woman works at a VDU for long hours, the unborn child in her body might be killed. Safety screens to put over a VDU have been invented but few companies in prefix = st1 /Englandbother to buy them.                                                                                          Whatever the arguments for and against word processor are, they are a key feature   of this revolution in office practice. Ten years ago, smaller companies did not use large computers because  _  .
A. these companies had not enough money to buy such expensive computers
B. these computers could not do the work that small computers can do today
C. these computers did not come onto the market
D. these companies did not need to use this new technology
Answer: