please help check

W:   i heard that only 20% of summer jobs in this part of the country are advertised. the other 80% are filled some other way.

M:   relaly? then maybe i need to change my jobsearch techniques.>>

Q:   what can be inferred about the man?

(A) He has been applying only for advertised jobs.>>

   (B) He’s conviced that there’s a shortage of jobs.>>

   (C) He doesn’t have time to read all the job ads.>>

   (D) He’ll help the woman find a job.

I choose a, but the answer is b.