If the I-140 is approved, choose A. If I-485 is filed concurrently with I-140, or while I-140 is pending, the form's design is unclear. Some people do A, and some people do H and write pending I-140, or concurrently filing with I-140. Both will work.
It is confusing because for I-485 concurrently filed with I-130, they do choose A, because it says "An immigrant petition giving me an immediately available immigrant visa number that has been approved. (Attach a copy of the approval notice, or a relative, special immigrant juvenile, or special immigrant military visa petition filed with this application that will give you an immediately available visa number, if approved.)" However, I-140 is an employer-based petition, which is not a relative, special immigrant juvenile, or special immigrant military petition, so it is technically not included in the sentence above (though the instruction is self-contradictory anyway, since it says a petition "has been approved" in one part but says you can attach a petition in another part). Logically, concurrent filing for I-140 and I-130 should work the same way, so A should be chosen for both. But since technically the part of the sentence about concurrent filing mentions relative but not employer petitions, you could argue that A is not applicable, and thus choose H (other).