【单选题】

Much unfriendly feeling towards computers has been based on the fear of widespread unemployment resulting from their introduction.Computers are often used as part of automated (自动化的) production systems requiring a least possible number of operators, causing the loss of many jobs. This has happened, for example, in many steelworks.

On the other hand, computers do create jobs. They are more skilled and better paid, though fewer in number than those they replace. Many activities could not continue in their present form without computers, no matter how many people are employeD、Examples are the check clearing (交换) system of major banks and the weather forecasting system.
When a firm introduces computers, a few people are usually employed in key posts (such as jobs of operations managers) while other staff are re-trained as operators, programmers, and data preparation staff. After the new system has settled down, people in non-computer jobs are not always replaced when they leave, resulting in a decrease in the number of employees. This decrease is sometimes balanced by a substantial increase in the activity of the firm, resulting from the introduction of computers.
The attitudes of workers towards computers vary. There is fear of widespread unemployment and of the takeover of many jobs by computer-trained workers, making promotion for older workers not skilled in computers more difficult.
On the other hand, many workers regard the trend toward wider use of computers inevitable. They realize that computers bring about greater efficiency and productivity, which will improve the condition of the whole economy, and lead to the creation of more jobs. This view was supported by the formerBritish Prime Minister, JamesCallaghan in 1979, when he made the point that new technologies hold the key to increased productivity, which will benefit the economy in the long run.
The underlined word “They” (Line 1, ParA、2) refers to______
A．computersB．jobs C．activities D．systems