I-129F Leaving Fields Blank If Not Applicable?

[SebastianOs 14]

I read on the instructions for the I-129F that if a question does not apply to you, you must put "N/A".  If it is a numeric question that is not applicable, then you must put "None" or "0".  But what about when it asks for the Apt., Ste., Flr., and then the following blank (ex. Part 1, 8c.)?  I do not live in an apartment so do I just put "N/A" or leave it blank?  Also, for questions like "You are a U.S. citizen through (select only one box):" They have items 40a - 40c. I answered 40a.  So, therefore, question 41 should be obviously not applicable.  Yet, there is no dedicated space for me to put "N/A".  Do I just write it next to the "Yes" box and "No" box? Thanks.

Edited March 12, 2018 by SebastianOs

[Ana_and_Derek 49]

I would leave the apartment field blank. And for #41, I was in the same situation as you. I decided to follow the example I-129F VisaJourney has and I checked no, despite being a US Citizen. 

[Nevad@ 26]

It is a good question... My fiance submitted the final form and I am not sure if he did out N/A's where needed or if he left them blank... How much does this matter?