Form 8889 is the form that reports activity in your HSA (Health Savings Account). The answer for you depends on whether you have an HSA or not.
***I do not have an HSA***
It is possible to accidentally indicate that you had an HSA when perhaps you didn't. If you really don't have HDHP (High Deductible Health Plan) coverage nor an HSA, then please do the following to remove all HSA information from your return.
Please do the following in this order:
1. make a copy of your W-2(s) (if you don't have the paper copies)
2. delete your W-2(s) (use the garbage can icon next to the W-2(s) on the Income screen
3. go to View (at the top), choose Forms, and select the desired form. Note the Delete Form button at the bottom of the screen.
*** Online ***
3. go to Tax Tools (on the left), and navigate to Tools->Delete a form
4. delete form(s) 1099-SA (if one), 8889-T, and 8889-S (if one)
5. go back and re-add your W-2(s), preferably adding them manually
6. go back and continue your return.
***I have an HSA***
The Line 18 Smart Worksheet is asking you for your HDHP coverage month by month in 2017. You almost certainly got the message that you had a lapse in coverage in 2018. This is because (1) you did not indicate that you had coverage in every month in 2018 in the HSA interview, and (2) you answered the question about HDHP coverage on December 1, 2017 with "Family" or "Self".
This is a legitimate question (if a bit odd), and if you did have HDHP coverage on 12/1/2017 and did not have HDHP coverage for every month in 2018, then you need to answer the question.
However, if you
- had HDHP coverage for every month in 2017 or
- had HDHP coverage for every month in 2018 or
- did not have HDHP coverage in 2017 or
- did not have an HSA in 2017
this question actually doesn't apply to you - just answer "None".