Thank you for doing a poll!
I voted for option 3 because why not give more options for those who may not want the pet. But I also voted for that assuming that the pet hatching item would still be available separately for those who might just want the pet. I'm pretty sure it would be since nothing was mentioned about it not being sold separately in that option but I wanted to clarify that. I don't want two chests if it's going to take away some other option we already have.
I also agree with the above that, if it's implemented, the icons of the two chests need to be very distinctly different from each other.