Unemployment rate fell from 8% to 7%. however, we cannot conclude that more people were unemployed(not working) than were employed. answer choice below should show how the number of unemployed people in 1886 >= number of unemployed people in 1881..
(A) The average time that employees stay in any one job dropped during the period 1881 to 1886
Average time one spent on one Job has dropped. It could be mean people are switching more often or it could mean they may be working long hours before and now reduced the no of hours. it could also mean people stopped working in between. however, it does not conclusively suggest reasoning to impact the conclusion.
(B) The total available work force, including those with and without employment, increased between 1881 and 1886
this option suggests total available workforce, meaning the number of people available to work (including employed and unemployed ) increased. Let's say available workforce was 100 in 1881, and unemployment rate 8% i.e 8 people were unemployed. and total available workforce in 1886 was 300. 7% of 200 = 14 . this proves why we cannot conclude above. keep the answer
(C) In some mid-western industrial states, the unemployment rate was much higher in 1886 than it had been in 1881
comparison with other states will not help compare the unemployment discussion in the two years of current state.
(D) Many of the high-paying industrial jobs available in 1881 were replaced by low-wage service jobs in 1886, resulting in displacement of hundreds of thousands of workers
many high paying jobs were replaced by low-wage service jobs. this resulted in displacement of many workers. displacement could mean removed from the jobs or relocated/moved from the current job. this also suggests if some people lost jobs , some gained jobs. it does not conclusively impact the conclusion
(E) help-wanted advertisements increased between 1881 and 1886
many jobs are available. availability of job does not indicate impact to people being employed or not employed. many jobs could not be fulfilled due to skills not matching and unemployment rate would still be high.
B is the sufficient answer