c. For an employer who has not been previously issued a stop-work order or order of penalty assessment, the department must reduce the final assessed penalty by 15 percent if the employer correctly answers at least 80 percent of the questions from an online workers' compensation coverage and compliance tutorial, developed by the department, within 21 days after the employer's receipt of the written request to produce business records for calculating the penalty under this subparagraph. The online tutorial must be taken in a department office location identified by rule. The $1,000 penalty shall be assessed against the employer even if the calculated penalty after the credit provided in sub-subparagraph a., the 25 percent reduction provided in sub-subparagraph b., and the 15 percent reduction provided in sub-subparagraph c., as applicable, have been applied is less than $1,000.