单项选择题

Stress is becoming an increasingly common feature of the workplace. Stress is a highly individual reaction, which varies considerably from person to person, and it is difficult for some employees to avoid it. Undoubtedly, changes in working conditions have led to greater pressure at work at all levels.
However, stress in itself is not harmful. Everyone needs a certain level of stress to enable him or her to feel motivated and to perform effectively. A complete absence of stress can be as damaging as overstress, since it can make people lose interest in their work, and even lead to depression. The difficulties occur when the amount of stress rises above a level which is healthy for a particular individual.
While it may not always be possible to prevent stress, there are a number of ways in which it can be controlled. The first thing that the trainees learn is how to manage their time effectively. This involves, first of all, setting realistic goals for both the short and long term. The trainees are also reminded that when they are under pressure the less important items should be left.
The trainees are encouraged to avoid being defensive, but at the same time they are advised not to be afraid of saying ’no’. They are asked to give reasons only if necessary. They learn, for example, to remind themselves that nothing terrible happens when a demand is refused or a deadline missed. Life goes on.
The passage is mainly about ______.