CREATE TABLE teaches (id VARCHAR(255), course_id VARCHAR(255)); CREATE TABLE course (course_id VARCHAR(255), title VARCHAR(255)); CREATE TABLE instructor (name VARCHAR(255), id VARCHAR(255))
Find the name of the instructors who taught C Programming course before.
    
SQL: SELECT T1.name FROM instructor AS T1 JOIN teaches AS T2 ON T1.id = T2.id JOIN course AS T3 ON T2.course_id = T3.course_id WHERE T3.title = 'C Programming'