Problem: 3 interviewers , x , y , and z are interviewing 40 applicants . only with 3 interviewers ' admission can an applicant be admitted . if interviewer x admitted 15 applicants , y admitted 17 applicants , and z admitted 20 applicants , at least how many applicants get the admission ? 
Options: a ) 0 , b ) 2 , c ) 6 , d ) 8 , e ) 12
a