I'd check I-551 box. Technically, you cannot use just I-797. It's not an ID, it linked to I-551 since it's extending it.
So you're showing expired GC (I-551) and I-797 which extends its validity.
Boring part
Also, very important, I-797 and I-797C are different things! Make sure you show original watermarked I-797 and not its black and white copy (I-797C).
Obviously, do not surrender I-797 for DMV to keep, as you'll need it for travel etc.
Also, I-797 and I-797A are also different things. I-797A is a replacement for I-94. I-797A is not issued for I-751. I-797 is issued, and I-797C (copy). I-797A is issued to non-immigrants, such as people on H1B etc.