Last year, when I was grading my students’ work, I would get this response from time to time.

I don’t know.

Here is my standard reply:

IDK.  If ever you encounter questions you cannot answer, check the “Student Answers” section under the “Members” tab of my site….  -5
Other students have gone before you.  Others have also struggled.  I have held on to their answers and I have held on to my responses to their answers.
Do some research.  Check out the Members tab of my site.  Pick your course.  Look for “Student Answers”.  Compare your work to theirs.
If you are really stuck, seek help in the forums.  Interact with others.