Among research postgraduate students, give the name of the course with the student satisfaction value of 1.
research postgraduate students refers to type = 'RPG'; name of the course refers to name; satisfaction refers to sat; sat = 1;
SELECT T3.name FROM student AS T1 INNER JOIN registration AS T2 ON T1.student_id = T2.student_id INNER JOIN course AS T3 ON T2.course_id = T3.course_id WHERE T2.sat = 1 AND T1.type = 'RPG'