CREATE TABLE voting_record (stuid DECIMAL, registration_date TEXT, election_cycle TEXT, president_vote DECIMAL, vice_president_vote DECIMAL, secretary_vote DECIMAL, treasurer_vote DECIMAL, class_president_vote DECIMAL, class_senator_vote DECIMAL)
CREATE TABLE student (stuid DECIMAL, lname TEXT, fname TEXT, age DECIMAL, sex TEXT, major DECIMAL, advisor DECIMAL, city_code TEXT)

Find the major that is studied by the most female students.
SELECT major FROM student WHERE sex = "F" GROUP BY major ORDER BY COUNT(*) DESC LIMIT 1
SELECT "major" FROM "student" WHERE "F" = "sex" GROUP BY "major" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1