Industrial accidents are more common when some of the people in safety-sensitive jobs have drinking problems than when none do.  Since, even after treatment, people who have had drinking problems are somewhat more likely than other people to have drinking problems in the future, any employer trying to reduce the risk of accidents should bar anyone who has ever been treated for a drinking problem from holding a safety-sensitive job.

Which of the following, if true, most seriously undermines the argument above?

1. Some companies place employees who are being treated for drinking problems in residential programs and allow them several weeks of paid sick leave.
2. Many accidents in the workplace are the result of errors by employees who do not hold safety-sensitive jobs.
3. Workers who would permanently lose their jobs if they sought treatment for a drinking problem try instead to conceal their problem and continue working for as long as possible.
4. People who hold safety-sensitive jobs are subject to stresses that can exacerbate any personal problems they may have, including drinking problems.
5. Some industrial accidents are caused by equipment failure rather than by employee error.

answer A. 我选不出。请帮忙。

The argument states that the risk of accidents would be reduced if people who has been

treated with drinking problems be barred from holding safty sensitive jobs.This argument is

based on the assumption that people with drinking problem will obtain treatment and the

employer can get the information about treatment.If employer would not hire a person with

treatment history of drinking problem, then any person with drinking problem may not want to

get any treatment because he does want to lose job.Hence C is the right answer.