My sister, a household member, has agreed to be a joint sponsor with me, however I'm not sure if she should use the I-864 or I-864A. She was not required to file taxes due to her SS income level. I noticed on the I-864A no option to indicate that, such as on the I-864, Part 6, line 17.
Would it be better to use the I-864 so she can note no tax filing required, and submit evidence to support that? If she is required to use the I-864A because she's a household member, is it acceptable to just submit evidence explaining the reason for no tax transcript?