What are names of instructors who advise students?
select t2.name from advisor as t1 join instructor as t2 on t1.i_id = t2.id
Of these, which one instructs the students with the most total credits?
select t2.name from advisor as t1 join instructor as t2 on t1.i_id = t2.id join student as t3 on t1.s_id = t3.id order by t3.tot_cred desc limit 1