First and foremost, supervisors a. counsel students on personal issues. b. control the environment. c. have the ability to teach the job you will be doing. d. advocate to make the team more efficient

First and foremost, supervisors have the ability to teach the job you will be doing.  This is so because, in order for a supervisor to provide good supervision in regard to determine whether those being supervised are performing well their jobs, supervisors will need to know how to perform the job themselves.   As such, because the will have most likely done the job well themselves in order to achieve a supervisory position, they would certainly have the ability to teach it to you.