Problem: In trying to delete from the employee table, what is the cause of this error: "Query failed because of: error: update or delete on table "employee" violates foreign key constraint "employee_reports_to_fkey" on table "employee"?
a.) The reports_to column links to the employee_id in the employee table that has the value that exists.
b.) The reports_to value of the row being deleted must be updated first.
c.) The customer table references the employee table, so the customer table data has to be removed first.
d.) The reports_to in the employee table doesn't exist.