The purpose of the post-test is to assess your knowledge and verify your understanding of the module's concepts. However, the purpose of the module is for your educational benefit. Therefore, you are allowed to take the post-test twice, if needed.
If, after taking the post-test the first time, you are not satisfied with your score, you may go back to review those sections in the module where you missed questions. You may then take the post-test a second time. If you elect to retake the post-test a second time, you agree to forfeit your score on the first attempt and it will no longer be available to you.