(1) Teachers created a Choice activity in a Moodle course, and set choice option limit to 1.

(2) The first student selected a choice in the Choice activity.

(3) The student is then removed from the course.

(4) The student record is still kept in mdl_choice_answers database table

(5) The second student selected the same choice in the Choice activity. There are two students choosing the same choice in mdl_choice_answers database table.

(6) The first student is then added back to the course.

(7) The total number of students choosing the same choice is now 2, which exceeded the choice option limit.