CREATE TABLE participates_in (stuid NUMBER, actid NUMBER)
CREATE TABLE faculty (facid NUMBER, lname CLOB, fname CLOB, rank CLOB, sex CLOB, phone NUMBER, room CLOB, building CLOB)
CREATE TABLE student (stuid NUMBER, lname CLOB, fname CLOB, age NUMBER, sex CLOB, major NUMBER, advisor NUMBER, city_code CLOB)
CREATE TABLE faculty_participates_in (facid NUMBER, actid NUMBER)
CREATE TABLE activity (actid NUMBER, activity_name CLOB)

What is the name of the activity with the most students?
SELECT T1.activity_name FROM activity AS T1 JOIN participates_in AS T2 ON T1.actid = T2.actid GROUP BY T1.actid ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T1"."activity_name" FROM "activity" "T1" JOIN "participates_in" "T2" ON "T1"."actid" = "T2"."actid" GROUP BY "T1"."actid" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY