Are these possible cracks or wood grain on a D10e

[Ralph124C41]

Can you feel it with your fingertip or fingernail? It could be a hairline crack or maybe a crack in the finish, but I doubt that. If I had to bet, I'd bet on it being a crack but as others have suggested, I'd take it to a local luthier or some knowledgeable guitar tech for a second opinion.

And I said "knowledgeable" because I've found some techs who are great on electrics but not so great on acoustics. And I've found some who are great on acoustics but not on electrics, mainly because of their limited knowledge about pickups and related doohickeys.

So in my area I have two "guys", one who works on my electrics and one, a luthier who makes his own brand of guitar, who works on my acoustics.

[MinTac]

Looks like a crack to me as it doesn't seem to be consistent with the surrounding wood grain. While in a darkened room you could put a flashlight in the sound hole, if that spot appears to have more light shining through than the surrounding wood it would indicate a crack that goes all the way through the top.

[RoyBoy]

It's definitely a crack. It's in a part of the top that generally has a LOT of cross grain support underneath, so unless this guitar is lacking that reinforcement there shouldn't be any structural strength concerns. If you found several others, then definitely return it. Perhaps the top wasn't sufficiently dry when the guitar went together (doesn't seem likely with Martin).

[JonWint]

Do a leak test. Does naphtha leak through it?

Put naphtha on the outside and look inside for wetting.