Among undergraduate students, list the name of the course with the highest student satisfaction.
Undergraduate students refers to type = 'UG'; satisfaction refers to sat; highest satisfaction refers to MAX(sat);
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 T1.type = 'UG' ORDER BY T2.sat DESC LIMIT 1