Reset Quiz attempt

I have made it about 2/3 of the quiz on Non Linear Analysis with Optistruct but i have failed my 3 attempts on Bolt Pretension.

I find it to have some ambiguous questions( ie does 1D pretension use rigid 1d elements ? , in my understanding it  has rigid 1D web in form of RBE2 but also uses non rigid as rod,bar,beam)  as well as some questions that are not entirely specified in any of the related Study books.

Either way i would appreciate if i could get another shot at the certificate.