explain bad grades to recommender I asked this professor for a recommendation letter. She told me to send her transcript, CV, statement of purpose and the thesis.
I have some bad grades (not in her class though) and don't know how to approach this:

option 1: in my email to her I will tell her the reason why I had those bad grades.
option 2: I just send her all the materials she asked of me without saying anything about the grades. In the statement of purpose, there were already 1-2 sentences explaining my performance in those classes, so if she reads it, she can understand the situation.
option 3: I send her the statement of purpose first. For the other materials, I will send them later. Then she will see   sop before the transcript
option 4:  I just send her all the materials she asked of me without saying anything about the grades. On the SOP, I don't mention my grade as well. Then, if she asks why my grade is bad, I will explain it to her.

Which one do you think is the best option, or do you recommend other alternatives?
Thank you all!
By asking for all of this information, it sounds like this professor is trying to write you a personalized letter, which is usually a good thing.  She's helping you out.
Therefore, it's completely reasonable to take option 1 and simply explain your bad grades to her.  I wouldn't go overboard here - she's not making a hiring/admitting decision regarding you.  But a few lines giving her some context for all the material she asked for is not at all amis.