It is often said that politeness costs nothing. In fact, it seems that a little more courtesy could (1) businesses ￡5 billion every year. (2) hearing the phrase "thank you" or "well done" means the same to staff (3) a modest pay rise, researchers say. Praise and (4) also makes employees more likely to work hard and stay in their jobs, saving on the cost of finding (5) .A third of 1,000 workers (6) by consulting firm White Water Strategies said they did not get thanked (7) when they did well, and a (n) (8) third said they were not thanked enough. In both cases, staff said they felt undervalued, meaning they were less likely to (9) themselves and were more likely to (10) employment elsewhere. According to the company, praising staff has the same (11) kick as a 1 percent pay rise—and (12) much cheaper for bosses. Three (13) four employees said that regular (14) by their bosses was important to them, (15) only a quarter said they were (16) given as much praise as they felt they needed. The survey found that those (17) blue-collar and manual jobs were less likely to (18) any recognition for doing well.Older employees and women need the most reassurance, according to psychologist Averil Leimon, a director of White Water Strategies. She said that words of praise did more than (19) a pleasant place to work—they could even (20) profits. 16（）

A. actually
B. absolutely
C. certainly
D. possibly