text: Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
  ### Context:
  CREATE TABLE courses (course_name VARCHAR, course_id VARCHAR); CREATE TABLE student_course_registrations (course_Id VARCHAR)
  ### Question:
  which course has most number of registered students?
  ### Answer:
  SELECT T1.course_name FROM courses AS T1 JOIN student_course_registrations AS T2 ON T1.course_id = T2.course_Id GROUP BY T1.course_id ORDER BY COUNT(*) DESC LIMIT 1