MySQL error 1241: Operand should contain 1 column, INTERSECT two subqueries
You probably want to replace:

WHERE cTitle='Database Management Systems'
IN (
SELECT S2.StuName, S2.StuID 
...
  ) ;


with:

WHERE cTitle='Database Management Systems'
  AND (S.StuName, S.StuID) IN (                -- this changed
SELECT S2.StuName, S2.StuID 
...
  ) ;