My wife is the only immigrant, and I am her only sponsor.
USCIS has step-by-step instructions for this form:
8. Indicate whether you are sponsoring the principal immigrant listed in item 2 in this Form I-864. This only applies to cases with two joint sponsors. Check "No" only if you are sponsoring only intended immigrants listed in 9 and not the principal immigrant listed in item 2.
This implies that I should NOT check the box next to "I am sponsoring the principal immigrant named in Part 2 above." and I should NOT check "Yes" NOR "No". In other words, I leave Part 3 blank? And I similarly write nothing for "Total number of immigrants you are sponsoring" there?
It seems a little strange (since I AM sponsoring the principal immigrant), so I was hoping for clarification?