Mock tests/ Foundation exams are useful to know your understanding of the concepts.

Thus, the discussion section is not made available on purpose. For a software developer, problem-solving skills are most important. If you depend on help, you cannot improve these skills.

Revise the concepts and try solving the questions again. It will help you to perform better in interviews.

If you need help understanding the concepts, you can post them under the respective course, so that the domain experts will help you.