Self-Employed with Social Sec. Income - Where enter Medicare B payments?

Hi,  Just checking.  I'm self-employed. I receive monthly social security where the Medicare B payments are deducted each month.  For the year's total of Medicare B pymts,  where do I enter?

Is it:  Under Business Expenses,  Health Insurance Premiums section?

Or:  Somewhere on Schedule A?

And what about Schedule C?

Thanks.