In 1924 America's National Research Council sent two engineers to supervise a series of industrial experiments at a large telephone-parts factory called the Hawthorne Plant near Chicago.It hoped they would learn how stop-floor lighting 1 workers'productivity.Instead,the studies ended 2 giving their name to the"Hawthorne effect",the extremely influential idea that the very 3 to being experimented upon changed subjects'behavior.The idea arose because of the 4 behavior of the women in the Hawthorne plant.According to 5 of the experiments,their hourly output rose when lighting was increased,but also when it was dimmed.It did not 6 what was done in the experiment;7 something was changed,productivity rose.A（n）8 that they were being experimented upon seemed to be 9 to alter workers'behavior 10 itself.After several decades,the same data were 11 to econometric the analysis.Hawthorne experiments has another surprise store 12the descriptions on record,no systematic 13 was found that levels of productivity were related to changes in lighting.It turns out that peculiar way of conducting the experiments may be have let to 14 interpretation of what happed.15,lighting was always changed on a Sunday.When work started again on Monday,output 16 rose compared with the previous Saturday and 17 to rise for the next couple of days.18,a comparison with data for weeks when there was no experimentation showed that output always went up on Monday,workers 19 to be diligent for the first few days of the week in any case,before 20 a plateau and then slackening off.This suggests that the alleged"Hawthorne effect"is hard to pin down.12选？
根据本空之前的句子，“霍桑实验还有另外一个让人意想不到的结果”得知，下面所说的内容应该是与记录中的一些描述相悖，因此需要一个表示转折的连接词。只有A项Contrary to表示“与……相反”，符合文意。
