A、Those of a small size. B、Those that are well managed. C、Those run by women. D、Those full of skilled workers. A浏览四个选项，根据选项中出现的s

W: Welcome to Workplace. And in today’s program, we’re looking at the results of two recently published surveys, which both deal with the same topic—happiness at work. John, tell us about the first survey.
M: Well, this was done by a human resources consultancy, who interviewed more than 1,000 workers, and established a top ten of the factors, which make people happy at work. [1] The most important factor for the majority of the people interviewed was having friendly, supportive colleagues. In fact, 73% of people interviewed put their relationship with colleagues as the key factor contributing to happiness at work, which is a very high percentage. The second most important factor was having work that is enjoyable. The two least important factors were having one’s achievements recognized, and rather surprisingly, earning a competitive salary.
W: So, we are not mainly motivated by money?
M: Apparently not.
W: Any other interesting information in the survey?
M: [2] Yes. For example, 25% of the working people interviewed described themselves as "very happy" at work. However, 20% of employees described themselves as being unhappy.
W: That’s quite a lot of unhappy people at work every day.
M: It is, isn’t it? And there were several more interesting conclusions revealed by the survey. First of all, small is beautiful: [3] people definitely prefer working for smaller organizations or companies with less than 100 staff. We also find out that, generally speaking, women were happier in their work than men.
W: Yes, we are, aren’t we?
M: [4] And workers on part-time contracts, who only work 4 or 5 hours a day, are happier than those who work full-time. The researchers concluded that this is probably due to a better work-life balance.
W: Are bosses happier than their employees?
M: Yes, perhaps not surprisingly, the higher people go in a company, the happier they are. So senior managers enjoy their jobs more than people working under them.
Questions 1 to 4 are based on the conversation you have just heard.
1. What is the No. 1 factor that made employees happy according to the survey?
2. What is the percentage of the people surveyed who felt unhappy at work?
3. What kind of companies are popular with employees?
4. What is the possible reason for people on part-time contracts to be happier?