Yes. You already posted about this and you know it is in the checklist. It is required. See my post in your other thread about how to obtain your Option C Printout.
If you have one or can get one, send it in.
If you don't have one and can't get one, send in a letter explaining why. Also send in any proof you have of your current job.
I didn't have an Option C when I sent in our application, because I didn't have a job that year and so didn't file income tax, but I was accepted as a sponsor and the visa officer never mentioned it.
Option C was one of the only things my husband was asked to do for the application and he didn't and so I included a letter and his pay stubs for the last 12 months and he was approved.