Which of the following both make a firm more likely to pay efficiency wages?
a. it is difficult to judge the quality of applicants and after workers have worked for the firm a while they tend to look for other jobs
b. it is easy to judge the quality of applicants and after workers have worked for the firm a while they tend to look for other jobs
c. it is difficult to judge the quality of applicants and after workers have worked for the firm a while they tend not to look for other jobs
d. it is easy to judge the quality of applicants and after workers have worked for the firm a while they tend not to look for other jobs.